Etymology
Advertisement
onto- 

word-forming element meaning "a being, individual; being, existence," from stem of Greek on (genitive ontos) "being," neuter present participle of einai "to be" (from PIE root *es- "to be").

Related entries & more 
Advertisement
zoo- 
word-forming element meaning "animal, living being," from Greek zoion "an animal," literally "a living being," from PIE root *gwei- "to live" (source also of Greek bios "life").
Related entries & more 
permeation (n.)

"act of permeating; state of being permeated," 1620s, noun of action from Latin permeare "to pass through" (see permeate).

Related entries & more 
in- (2)
Origin and meaning of in-

element meaning "into, in, on, upon" (also im-, il-, ir- by assimilation of -n- with following consonant), from Latin in- "in," from PIE root *en "in."

In Old French (and hence in Middle English) this often became en-, which in English had a strong tendency to revert to Latin in-, but not always, which accounts for pairs such as enquire/inquire. There was a native form, which in West Saxon usually appeared as on- (as in Old English onliehtan "to enlighten"), and some of those verbs survived into Middle English (such as inwrite "to inscribe"), but all now seem to be extinct.

Not related to in- (1) "not," which also was a common prefix in Latin, causing confusion: to the Romans impressus could mean "pressed" or "unpressed;" inaudire meant "to hear," but inauditus meant "unheard of;" in Late Latin investigabilis could mean "that may be searched into" or "that cannot be searched into." Latin invocatus was "uncalled, uninvited," but invocare was "to call, appeal to."

The trouble has continued in English; the hesitation over what is meant by inflammable being a commonly cited example. Implume (1610s) meant "to feather," but implumed (c. 1600) meant "unfeathered." Impliable can mean "capable of being implied" (1865) or "inflexible" (1734). Impartible in 17c. could mean "incapable of being divided" or "capable of being imparted." Impassionate can be "free from passion" or it can mean "strongly stirred by passion." Inanimate (adj.) is "lifeless," but Donne uses inanimate (v.) to mean "infuse with life or vigor." Irruption is "a breaking in," but irruptible is "unbreakable."

In addition to improve "use to one's profit," Middle English also had a verb improve meaning "to disprove" (15c.). To inculpate is "to accuse," but inculpable means "not culpable, free from blame." Infestive has meant "troublesome, annoying" (1560s, from infest) and "not festive" (1620s). In Middle English inflexible could mean "incapable of being bent" or "capable of being swayed or moved." In 17c., informed could mean "current in information," formed, animated," or "unformed, formless" ("This was an awkward use" [OED]). Inhabited has meant "dwelt in" (1560s) and "uninhabited" (1610s); inhabitable likewise has been used on opposite senses, a confusion that goes back to Late Latin.

Related entries & more 
cn- 

initial consonant combination used in Old English (the Clark Hall dictionary has 82 entries under cn-), but not now admitted in speech, the n- only being sounded. In Middle English spelling all were lost or turned to kn-. It also is retained in the spelling of some Latinized words from Greek, where initial kn- was common.

Related entries & more 
Advertisement
andro- 

word-forming element meaning "man, male, masculine," from Greek andro-, combining form of anēr (genitive andros) "a man, a male" (as opposed to a woman, a youth, or a god), from PIE root *ner- (2) "man," also "vigorous, vital, strong."

Equivalent to Latin vir (see virile). Sometimes in later use it was equivalent to Greek anthrōpos, Latin homo "a person, a human being," and in compounds it often retain this genderless sense (e.g. androcephalous "having a human head," said of monsters including the Sphinx, which in Greece was female).

Related entries & more 
anthropo- 

before a vowel, anthrop-, word-forming element meaning "pertaining to man or human beings," from Greek anthrōpos "man; human being" (including women), as opposed to the gods, from andra (genitive andros), Attic form of Greek anēr "man" (as opposed to a woman, a god, or a boy), from PIE root *ner- (2) "man," also "vigorous, vital, strong."

Anthropos sometimes is explained as a compound of anēr and ōps (genitive ōpos) "eye, face;" so literally "he who has the face of a man." The change of -d- to -th- is difficult to explain; perhaps it is from some lost dialectal variant, or the mistaken belief that there was an aspiration sign over the vowel in the second element (as though *-dhropo-), which mistake might have come about by influence of common verbs such as horao "to see." But Beekes writes, "As no IE explanation has been found, the word is probably of substrate origin."

Related entries & more 
e- 

the later Romans evidently found words beginning in sc-, sp-, st- difficult or unpleasant to pronounce; in Late Latin forms begin to emerge in i- (such as ispatium, ispiritu), and from 5c. this shifted to e-. The development was carried into the Romanic languages, especially Old French, and the French words were modified further after 15c. by natural loss of -s- (the suppression being marked by an acute accent on the e-), while in other cases the word was formally corrected back to the Latin spelling (for example spécial). Hence French état for Old French estat for Latin status, etc. It also affected Romanic borrowings from Germanic (such as espy, eschew).

A different e- is a reduced form of Latin ex- before consonants (see ex-), and the e- in enough is an unfelt survival of an Old English alternative form of ge-.

Related entries & more