simple past tense and past participle of restrain
"The security guard restrained the suspect before he could break free from his bonds."
cool and formal in manner
"The general maintained a restrained demeanor throughout the chaotic event, speaking softly while others shouted around him."
under restraint
"The police officer kept his hands behind his back while he was restrained in handcuffs during the arrest."
marked by avoidance of extravagance or extremes
"moderate in his demands"
"restrained in his response"
Held back, limited, kept in check or under control.
"She kept her anger restrained even though his comments were deeply hurtful."