The verb пахать means to plough.As in to plough land.
Its other idiomatic expression means:
1)to work
2)to tire one's ass off at work
First you can use the verb when u want to say for instance:
1) Does your email work?
Твой е-мейл пашет?
2) Yeh im workin my ass off at work damn it
Вот я пашу на работе блин
3) We're ploughing farrow land
Мы пашем под пар