Incommunicative /(?)/
In·com·mu·ni·ca·tive
Incommunicative
a.
-
Not communicative; not free or apt to impart to others in conversation; reserved; silent; as, the messenger was incommunicative; hence, not disposed to hold fellowship or intercourse with others; exclusive.
The Chinese . . . an incommunicative nation.
His usual incommunicativeness.