go: [OE] Go is an ancient verb, traceable back to a prehistoric Indo-European base *ghēi- or *ghē-. This seems to have been relatively unproductive outside the Germanic languages (Sanskrit hā-, hī- ‘leave’ and Greek kikhánō ‘reach’ may be descendants of it), but it has provided the basic word for ‘move along, proceed’ in all the Germanic languages, including German gehen, Dutch gaan, Swedish gā, Danish gaa, and English go. In Old and Middle English its past tense was ēode, later yode, a word of uncertain origin, but from about 1500 this was replaced by went, originally the past tense of wend.
Old English gan "to advance, walk; depart, go away; happen, take place; conquer; observe, practice, exercise," from West Germanic *gaian (cognates: Old Saxon, Old Frisian gan, Middle Dutch gaen, Dutch gaan, Old High German gan, German gehen), from PIE *ghe- "to release, let go" (cognates: Sanskrit jihite "goes away," Greek kikhano "I reach, meet with"), but there does not seem to be general agreement on a list of cognates.
A defective verb throughout its recorded history; the Old English past tense was eode, a word of uncertain origin but evidently once a different verb (perhaps connected to Gothic iddja); it was replaced 1400s by went, 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. Meaning "cease to exist" is from c. 1200; that of "to appear" (with reference to dress, appearance, etc.) is from late 14c.; that of "to be sold" is from early 15c. Meaning "to be known" (with by) is from 1590s; that of "pass into another condition or state" is from 1580s. From c. 1600 as "to wager," hence also "to stand treat," and to go (someone) better in wagering (1864). Meaning "say" emerged 1960s in teen slang. Colloquial meaning "urinate or defecate" attested by 1926, euphemistic (compare Old English gong "a privy," literally "a going").
To go back on "prove faithless to" is from 1859; to go under in the figurative sense "to fail" is from 1849. To go places "be successful" is by 1934.
1727, "action of going," from use of go (v.) to start a race, etc. Meaning "an incident, an occurrence, affair, piece of business" is from 1796. Meaning "power of going, dash, vigor" is from 1825, colloquial, originally of horses. The sense of "an attempt, a try or turn at doing something" (as in give it a go, have a go at) is from 1825 (earlier it meant "a delivery of the ball in skittles," 1773). Meaning "something that goes, a success" is from 1876. Phrase on the go "in constant motion" is from 1843. Phrase from the word go "from the beginning" is by 1834. The go "what is in fashion" is from 1793. No go "of no use" is from 1825.