Green’s Dictionary of Slang

shaft v.

[SE shaft, to shoot with an arrow]

1. [1950s+] to have sexual intercourse (usu. of a man with a woman).

2. [1950s+] (orig. US) to defeat, to defraud, to harm, to treat unfairly.

3. [1990s+] (US campus) to steal.

4. [2000s] to stab.

In derivatives

shaftable (adj.)

[1950s+] of a woman, suitable for and hopefully susceptible to seduction.