Finished, complete with nothing missing (7)

I believe the answer is:

through

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

'finished' is the definition.
(similar in meaning)

I don't understand the remainder of the clue.

(Other definitions for through that I've seen before include "By means of; having finished a relationship" , "From beginning to end" , "having arrived at next stage" , "clear" , "Using" .)

I've seen this clue in The Guardian.

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.