Crossword Genius

An expression of congratulation to a smart individual (4,3)

Ross

I believe the answer is:

nice one

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

'an expression of congratulation' is the definition.
I know nothing about this answer so I can't tell whether it can be defined by this definition.

'smart individual' is the wordplay.
'smart' becomes 'nice' (I can't explain this - if you can you should believe this answer much more).
'individual' becomes 'one' (an individual is one person).
'nice'+'one'='NICE ONE'

'to a' is the link.

Can you help me to learn more?

(Other definitions for nice one that I've seen before include "like it!" , "Congratulatory phrase" , "very good" .)

I've seen this clue in the Evening Standard.
Want a hint initially instead of a full solution? Install my app