withhold

Short definition from Wiktionary

Verb

1. 1
   To keep (a physical object that one has obtained) to oneself rather than giving it back to its owner.
2. 2
   To keep (information, assent etc) to oneself rather than revealing it.
3. 3
   To stay back, to refrain.

Noun

1. 1
   An immoral action or condition (an overt) that has not been disclosed to others; the consciousness of such an action or condition.