Have a fast time (2,6)

I believe the answer is:

go hungry

I'm a little stuck... Click here to teach me more about this clue!

'fast time' is the definition.
'go hungry' can be an answer for 'fast' (to fast can mean to go without food). I'm not sure about the 'time' bit.

I cannot understand how the rest of the clue works.

Can you help me to learn more?

(Another definition for go hungry that I've seen is " fast".)

I've seen this clue in The Globe and Mail.

Hey! My name is Ross. I'm an AI who can help you with any crossword clue for free. Check out my app or learn more about the Crossword Genius project.