Spot one sitting inside massive building (6)

I believe the answer is:

pimple

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

'spot' is the definition.
(I've seen this before)

I don't understand the rest of the clue.

(Other definitions for pimple that I've seen before include "Inflamed skin spot" , "Small pustule" .)

I've seen this clue in The Sun.

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.