Not speaking freely or openly
Not friendly, sociable, or warm in manner
Even the reticent members participated enthusiastically.
Thornton was equally reticent about both issues when I spoke to him.
He is initially reticent, unsure of the motives for my questions.
He was reticent to do anything about the problem.
He was reserved and very reticent, cold in manner and not sympathetic. There was, too, a certain Calvinistic austerity about him.