large, long-tailed, stalk-eyed, 10-legged marine shellfish (Homarus vulgaris), early Middle English lopster, lopister, from Old English loppestre "lobster," also "locust," a corruption of Latin locusta, lucusta "marine shellfish, lobster;" also "locust, grasshopper," which is of unknown origin. De Vaan writes that "The only word similar in form and meaning is lacerta 'lizard; mackerel', but there is no common preform in sight. ... [T]hey could be cognate words in the language from which Latin borrowed these forms."
The change of Latin -c- to English -p- (and, from late 14c., to -b-) is unexplained; perhaps it is by influence of Old English loppe, lobbe "spider." The ending seems to have been altered by the old fem. agent noun suffix (preserved in Baxter, Webster, etc.; see -ster), which approximated the sound of Latin -sta.
OED says the Latin word originally meant "lobster or some similar crustacean, the application to the locust being suggested by the resemblance in shape." Trilobite fossils in Worcestershire limestone quarries were known colloquially as locusts, which seems to have been the generic word for "unidentified arthropod" (as apple was for "foreign fruit"). Locusta in the sense "lobster" also appears in Old Cornish legast and French langouste (12c.), now "crawfish, crayfish," but in Old French both "lobster" and "locust" (a 13c. psalter has God giving over the crops of Egypt to the langoustes).
As slang for "a British soldier" since 1640s, originally in reference to the jointed armor of the Roundhead cuirassiers, later (1660) to the red coat, the color of a boiled lobster.
Sir William Waller having received from London [in June 1643] a fresh regiment of five hundred horse, under the command of sir Arthur Haslerigge, which were so prodigiously armed that they were called by the other side the regiment of lobsters, because of their bright iron shells with which they were covered, being perfect curasseers. [Lord Clarendon, "History of the Rebellion," 1647]
[The egomaniac, as opposed to the megalomaniac,] does not regard it as necessary to dream of himself as occupying some invented social position. He does not require the world or its appreciation to justify in his own eyes himself as the sole object of his own interest. He does not see the world at all. Other people simply do not exist for him. The whole 'non-Ego' appears in his consciousness merely as a vague shadow or a thin cloud. The idea does not even occur to him that he is something out of the common, that he is superior to other people, and for this reason either admired or hated ; he is alone in the world ; more than that, he alone is the world and everything else, men, animals, things are unimportant accessories, not worth thinking about. [Max Nordau, "Degeneration," English translation, 1895]
Nordau's book was much-read, debated, and cited at the time and the word was associated with him (e.g. The Agora, July 1895).
Walker's use aside, its infrequent print appearance before 1895 seems to have been largely in the side of medicine that dealt with psychological matters:
The most frequent, yet the most extraordinary of these perversions of temper, are seen in young females. It is a species of aberration of the intellect, but short of insanity, real enough, but exaggerated, fictitious, factitious, and real at the same time. It frequently has its origin in dyspepsia, hysteria, or other malady, and in emotion of various kinds, such as disappointment, vexation, &c. Its object is frequently to excite and to maintain a state of active sympathy and attention, for which there, is as it were, a perpetual, morbid, and jealous thirst. It was rather aptly designated, by the clever relative of one patient, an ego-mania. [Marshall Hall, M.D., "Practical Observations and Suggestions in Medicine," London, 1845]
Middle English quene, "pre-eminent female noble; consort of a king," also "female sovereign, woman ruling in her own right," from Old English cwen "queen, female ruler of a state; woman; wife," from Proto-Germanic *kwoeniz (source also of Old Saxon quan "wife," Old Norse kvaen, Gothic quens), ablaut variant of *kwenon (source of quean), from PIE root *gwen- "woman."
The most ancient Germanic sense of the word seems to have been "wife," which had specialized by Old English times to "wife of a king." In Old Norse the cognate word was still mostly "a wife" generally, as in kvan-fang "marriage, taking of a wife," kvanlauss "unmarried, widowed," kvan-riki "the domineering of a wife."
In reference to anything personified as chief or greatest, and considered as possessing female attributes, from late Old English. Figuratively, of a woman who is chief or pre-eminent among others or in some sphere by 1590s. Queen-mother "widow of a king who is also the mother of a reigning sovereign" is by 1570s (colloquial queen mum is by 1960).
English is one of the few Indo-European languages to have a word for "queen" that is not a feminine derivative of a word for "king." The others are Scandinavian: Old Norse drottning, Danish dronning, Swedish drottning "queen," in Old Norse also "mistress," but these also are held to be ultimately from male words, such as Old Norse drottinn "master."
The chess piece (with the freest movement and thus the most power in attack) was so called from c. 1400. As a verb in chess, in reference to a pawn that has reached the opponent's side of the board and become a queen (usually), from 1789. The playing card was so called from 1570s.
Of bees from c. 1600 (until late 17c., they generally were thought to be kings; as in "Henry V," I.ii, but the Anglo-Saxons knew better: their word was beomodor); queen bee "fully developed female bee," the mother of the hive, is used in a figurative sense by 1807.
Meaning "male homosexual" (especially a feminine and ostentatious one) is certainly recorded by 1924; probably as an alteration or misunderstanding of quean, which is earlier in this sense but had become obscure. Cincinnati, Ohio, has been the Queen City (of the West) since 1835. In commercial reference to an extra-large bed size (but generally smaller than king), by 1954.
"quadruped of the genus Canis," Old English docga, a late, rare word, used in at least one Middle English source in reference specifically to a powerful breed of canine; other early Middle English uses tend to be depreciatory or abusive. Its origin remains one of the great mysteries of English etymology.
The word forced out Old English hund (the general Germanic and Indo-European word, from root from PIE root *kwon-) by 16c. and subsequently was picked up in many continental languages (French dogue (16c.), Danish dogge, German Dogge (16c.)). The common Spanish word for "dog," perro, also is a mystery word of unknown origin, perhaps from Iberian. A group of Slavic "dog" words (Old Church Slavonic pisu, Polish pies, Serbo-Croatian pas) likewise is of unknown origin.
In reference to persons, by c. 1200 in abuse or contempt as "a mean, worthless fellow, currish, sneaking scoundrel." Playfully abusive sense of "rakish man," especially if young, "a sport, a gallant" is from 1610s. Slang meaning "ugly woman" is from 1930s; that of "sexually aggressive man" is from 1950s.
Many expressions — a dog's life (c. 1600), go to the dogs (1610s), dog-cheap (1520s), etc. — reflect the earlier hard use of the animals as hunting accessories, not pets. In ancient times, "the dog" was the worst throw in dice (attested in Greek, Latin, and Sanskrit, where the word for "the lucky player" was literally "the dog-killer"), which plausibly explains the Greek word for "danger," kindynos, which appears to be "play the dog" (but Beekes is against this).
Notwithstanding, as a dog hath a day, so may I perchance have time to declare it in deeds. [Princess Elizabeth, 1550]
Meaning "something poor or mediocre, a failure" is by 1936 in U.S. slang. From late 14c. as the name for a heavy metal clamp of some kind. Dog's age "a long time" is by 1836. Adjectival phrase dog-eat-dog "ruthlessly competitive" is by 1850s. Phrase put on the dog "get dressed up" (1934) may be from comparison of dog collars to the stiff stand-up shirt collars that in the 1890s were the height of male fashion (and were known as dog-collars from at least 1883).
And Caesar's spirit, ranging for revenge,
With Ate by his side come hot from Hell,
Shall in these confines with a monarch's voice
Cry Havoc! and let slip the dogs of war;
[Shakespeare, "Julius Caesar"]