Show undue pride, having left the butter out? (5)

I believe the answer is:

gloat

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

'show undue pride' is the definition.
Although both the answer and definition are singular nouns, I cannot understand how one could define the other.

'left the butter out?' is the wordplay.
'left' becomes 'L' (common abbreviation).
'the butter' becomes 'goat' (animal which butts).
'out?' indicates putting letters inside.
'l' going inside 'goat' is 'GLOAT'.

'having' is the link.

Can you help me to learn more?

(Other definitions for gloat that I've seen before include "Exult over one's good fortune" , "Look triumphant" , "Exult maliciously" , "Look like the cat who got the cream" , "Be full of malicious delight" .)

I've seen this clue in the Evening Standard.

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.