uncommunicative

Example:The shy student was reticent about participating in class discussions.

Definition:Tending to keep silent or speaking very little; usually applied to people who are cautious in expressing their thoughts and opinions.

Example:The reserved nature of the new team member made it difficult for others to get to know him.

Definition:Hesitant in making oneself known or known; cautious in one's opinions, feelings, and behavior.

Example:Due to his mute behavior, it was hard to initiate a conversation with him.

Definition:Unable to, or unwilling to speak; silent.