"reticent" in the adjective sense
1. reticent, untalkative
temperamentally disinclined to talk
2. restrained, reticent, unemotional
cool and formal in manner
3. reticent, self-effacing, retiring
reluctant to draw attention to yourself
Source: WordNet® (An amazing lexical database of English)
Princeton University "About WordNet®."
WordNet®. Princeton University. 2010.
View WordNet® License