closemouthed

listen to the pronunciation of closemouthed
Englisch - Türkisch
ağzı sıkı
konuşmaz
sIkI ağızlı
Englisch - Englisch
reticent, secretive or uncommunicative

Instructors were notoriously closemouthed about their gunnery techniques.

Cautious in speaking; secret; wary; uncommunicative
{s} silent, quiet, reserved, not talkative