Anxious nipper heaves up (12)

I believe the answer is:

apprehensive

'anxious' is the definition.
(synonyms)

'nipper heaves up' is the wordplay.
'up' is an anagram indicator (letters get chucked up).
'nipper'+'heaves'='nipperheaves'
'nipperheaves' anagrammed gives 'APPREHENSIVE'.

(Other definitions for apprehensive that I've seen before include "Seven happier (anag.)" , "Worried" , "Fearful, anxious" , "Uneasy, anxious" , "Feeling anxiety or fear about future events" .)

I've seen this clue in The Independent.

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.