Often followed by to: hesitancy or reluctance (to do something).
Followed by of: discretion or restraint in the use of something.
Avoidance of saying or reluctance to say too much; discretion, tight-lippedness; (countable) an instance of acting in this manner.
A silent and reserved nature.
To deliberately not listen or pay attention to; to disregard, to ignore.
The trait of being taciturn.
Failure to assert a legal right in a way that implies that it is being given up.