nice nellie nice Nelly1 n.,
informal Someone who acts too good to be true; a prude; a prig.
We took him for a nice Nelly when he wouldn't fight.nice Nelly2 adj.,
informal Too careful not to say or do anything wrong or improper; too proper; prudish.
Her nice Nelly behavior made her unpopular at school. [TahlilGaran] English Idioms Dictionary ▲