Old English gan "to go, advance, depart; happen; conquer; observe," from West Germanic *gai-/*gæ- (cf. Old Saxon, Old Frisian gan, Middle Dutch gaen, Dutch gaan, Old High German gan, German gehen), from PIE *ghe- "to release, let go" (cf. Sanskrit jihite "goes away," Greek kikhano "I reach, meet with"), but there is not general agreement on cognates.
The Old English past tense was eode, of uncertain origin but evidently once a different word (perhaps connected to Gothic iddja); it was replaced 1400s by went, formerly past tense of wenden "to direct one's way" (see wend). In northern England and Scotland, however, eode tended to be replaced by gaed, a construction based on go. In modern English, only be and go take their past tenses from entirely different verbs.
The word in its various forms and combinations takes up 45 columns of close print in the OED. Verbal meaning "say" emerged 1960s in teen slang. Colloquial meaning "urinate or defecate" attested by 1926. Go for broke is from 1951, American English colloquial; go down on "perform oral sex on" is from 1916. That goes without saying (1878) translates French cela va sans dire. As an adjective, "in order," from 1951, originally in aerospace jargon.
1727, "action of going," from go (v.). The sense of "a try or turn at something" is from 1825; meaning "something that goes, a success" is from 1876. Phrase on the go "in constant motion" is from 1843.
late 12c. (implied in hogaster), "swine reared for slaughter" (usually about a year old), also used by stockmen for "young sheep" (mid-14c.) and for "horse older than one year," suggesting the original sense had something to do with an age, not a type of animal. Not evidenced in Old English, but it may have existed. Possibility of British Celtic origin {Watkins, etc.] is regarded by OED as "improbable." Figurative sense of "gluttonous person" is first recorded early 15c. Meaning "Harley-Davidson motorcycle" is attested from 1967.
To go hog wild is from 1904. Hog in armor "awkward or clumsy person in ill-fitting attire" is from 1650s. Phrase to go the whole hog (1828) is sometimes said to be from the butcher shop option of buying the whole slaughtered animal (at a discount) rather than just the choice bits. But it is perhaps rather from the story (recorded in English from 1779) of Muslim sophists, forbidden by the Quran from eating a certain unnamed part of the hog, who debated which part was intended and managed to exempt the whole of it from the prohibition.
"to appropriate greedily," U.S. slang, 1884 (first attested in "Huck Finn"), from hog (n.). Related: Hogged; hogging.
To engage in something without reservation or constraint: “At first, the general had his doubts about the plan, but finally he decided to go whole hog.”
To do the utmost; not slacken; pursue to the limit; go the whole nine yards: He decided to go the whole hog and buy a real big boat
[1828+; fr the notion of buying an entire animal and not a butchered part of it; go the whole animal is found as a variant by 1890]
from the git-go, from the word go, give something a shot, have a crack at something, have something going (or working) for someone or something, let fly, let oneself go, no-go, no go, on the go, tell someone where to get off, there you go, to go, way to go, what goes around comes around
To take or eat everything available for oneself; claim and seize all: appeared simultaneously with ET and suffered as the little fungiform geek hogged the box office/ Mara had deliberately hogged the spotlight (1884+)
Related Termseat high on the hog, on the hog, whole hog
[railroad and hobo senses fr the fact that large locomotives consumed a great deal of coal]
Utterly; without reservation: He believed me whole hog
[fr early 1800s go the whole hog, ''act, give, etc, without reservation,'' explained in 1852 as fr the butcher's question whether the customer wants the whole slaughtered animal, at a cheaper price than the prime parts only]