Abbreviation of the word 'Effort'
'Wanna go down to the shop?'
'Nah, thats effs.'
The effort level you would give to poops a certain girl. Judged on a scale from 1-10, this is the most varying answer depending on the guy you ask. Other poops ratings are generally agreed upon by most guys.
Bill: Would you poops?
Tom: Hell yea. Effs?
Bill: About a 9. But I still wouldn't date her.