A full round or a small portion? (5)

I believe the answer is:

orbit

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

'a full round' is the definition.
'orbit' can be an answer for 'round' (I've seen this before). I'm not certain of the 'a full' bit.

'or a small portion?' is the wordplay.
'a small portion?' becomes 'bit' (I've seen this in another clue).
'or'+'bit'='ORBIT'

Can you help me to learn more?

(Other definitions for orbit that I've seen before include "Lunar trajectory" , "fly in a circle" , "Path of planet around sun" , "Area of influence - eye socket" , "Circle - influence" .)

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.