I. nig ‧ gle 1 /ˈnɪɡ ə l/ BrE AmE verb
[ Date: 1600-1700 ; Origin: Perhaps from a Scandinavian language ]
1 . [transitive] if something niggles you, you keep worrying about it or feeling annoyed about it and you cannot forget it ⇨ bug :
Something’s been niggling her all day.
It niggles me that we can’t go home yet and get warm.
2 . [intransitive] to argue or make criticisms about small unimportant details:
She niggled over every detail of the bill.
II. niggle 2 BrE AmE noun [countable]
1 . a slight feeling:
a niggle of doubt
2 . a slight criticism or complaint
3 . a slight physical pain:
a niggle in his knee