What is the meaning of 行く?

to go; to come to one's place

to (a letter) be delivered

to depart

to rely (on a method)

() to age

(うまく) to go well

After the て-form of a verb:

  1. to continue to do something; to go on to do something
  2. to gradually do something

to continue to do something; to go on to do something

to gradually do something

イく: to have an orgasm, to come, to cum

Source: wiktionary.org