go it v.
1. [late 17C; mid-19C+] to move at great speed.
2. [late 18C+] (also go it hot) to commit oneself fully, usu. to a course of self-indulgent pleasure or as in a fight.
3. [early 19C] to work as a prostitute.
4. [mid-19C] constr. with for, to offer one’s support.
5. [mid-late 19C] to fight physically or verbally.
6. [late 19C+] (Aus.) to accept, to believe in.
7. to masturbate.
[mid-19C–1900s] (US) to enter on an undertaking without proper preparation or planning.
see sense 2 above.
see come it strong under come it v.1