"artificial penis used for female gratification," 1590s, a word of unknown origin. Traditional guesses include a corruption of Italian deletto "delight" (from Latin dilectio, noun of action from diligere "to esteem highly, to love;" see diligence) or a corruption of English diddle. None of these seems very convincing (Florio's dictionary glosses many words with dildo, but diletto is not one of them.) Century Dictionary perhaps gets closer to the mark:
A term of obscure cant or slang origin, used in old ballads and plays as a mere refrain or nonsense-word; also used, from its vagueness, as a substitute for various obscene terms and in various obscene meanings. 
The earliest use of the word in this sense, and probably the start of its popularity, seems to be via Nashe:
"Curse Eunuke dilldo, senceless counterfet" ["Choise of Valentines or the Merie Ballad of Nash his Dildo," T. Nashe, c. 1593]
Other early forms include dildoides (1675), dildidoes (1607). Middle English had dillidoun (n.) "a darling, a pet" (mid-15c.), from Old Norse dilla "to lull" (hence dillindo "lullaby"). That sense probably survived into Elizabethan times, if it is the word in Jonson's "Cynthia's Revels":
Chorus: Good Mercury defend vs.
Phan.: From perfum'd Dogs, Monkeys, Sparrowes, Dildos, and Parachitos.
And dildin seems to be a term for "sweetheart" in a 1675 play:
Mir.: Here comes a lusty Wooer, my dildin, my darling.
Here comes a lusty Wooer Lady bright and shining.
The thing itself is older. A classical Latin word for one was fascinum (see fascinate). In later English sometimes a French word, godemiché, was used (1879). Also used in 18c. of things that resemble dildoes, e.g. dildo pear (1756), dildo cactus (1792).
Shakespeare plays on the double sense, sexual toy and ballad refrain, in "A Winter's Tale."
SERVANT: He hath songs for man or woman, of all sizes; no
milliner can so fit his customers with gloves: he
has the prettiest love-songs for maids; so without
bawdry, which is strange; with such delicate
burthens of dildos and fadings, 'jump her and thump
her;' and where some stretch-mouthed rascal would,
as it were, mean mischief and break a foul gap into
the matter, he makes the maid to answer 'Whoop, do me
no harm, good man;' puts him off, slights him, with
'Whoop, do me no harm, good man.'
late Old English wyrre, werre "large-scale military conflict," from Old North French werre "war" (Old French guerre "difficulty, dispute; hostility; fight, combat, war;" Modern French guerre), from Frankish *werra, from Proto-Germanic *werz-a- (source also of Old Saxon werran, Old High German werran, German verwirren "to confuse, perplex"), from PIE *wers- (1) "to confuse, mix up". Cognates suggest the original sense was "to bring into confusion."
Spanish, Portuguese, and Italian guerra also are from Germanic; Romanic peoples turned to Germanic for a "war" word possibly to avoid Latin bellum (see bellicose) because its form tended to merge with bello- "beautiful." There was no common Germanic word for "war" at the dawn of historical times. Old English had many poetic words for "war" (wig, guð, heaðo, hild, all common in personal names), but the usual one to translate Latin bellum was gewin "struggle, strife" (related to win (v.)).
First record of war-time is late 14c. Warpath (1775) originally is in reference to North American Indians, as are war-whoop (1761), war-paint (1826), and war-dance (1757). War crime is attested from 1906 (in Oppenheim's "International Law"). War chest is attested from 1901; now usually figurative. War games translates German Kriegspiel (see kriegspiel).
The causes of war are always falsely represented ; its honour is dishonest and its glory meretricious, but the challenge to spiritual endurance, the intense sharpening of all the senses, the vitalising consciousness of common peril for a common end, remain to allure those boys and girls who have just reached the age when love and friendship and adventure call more persistently than at any later time. The glamour may be the mere delirium of fever, which as soon as war is over dies out and shows itself for the will-o'-the-wisp that it is, but while it lasts no emotion known to man seems as yet to have quite the compelling power of this enlarged vitality. [Vera Brittain, "Testament of Youth"]
The world will never have lasting peace so long as men reserve for war the finest human qualities. [John Foster Dulles, Speech on the Marshall Plan, 1948]