1. Cool and formal in manner
   - reticent, unemotional 
2. Under restraint 
3. Marked by avoidance of extravagance or extremes
   "restrained in his response"
   - moderate 
4. Not showy or obtrusive
   - quiet 
5. Prudent
   - guarded

1. Keep under control; keep in check
   - keep, keep back, hold back 
2. Place limits on (extent or access)
   - restrict, trammel, limit, bound, confine, throttle 
3. To close within bounds, limit or hold back from movement
   - confine, hold 
4. Hold back
   - encumber, cumber [archaic], constrain 
5. To compel or deter by or as if by threats
   - intimidate

See also: cautious, close, controlled, inhibited, low-key, low-keyed, reserved, restrainer, restraint, subdued, temperate, undemonstrative, unexpansive, unostentatious, unpretending, unpretentious

Type of: bottle up, check, contain, control, curb, disable, discourage, disenable, hold, hold in, incapacitate, inhibit, moderate, suppress

Antonym: unrestrained

• mellifluous
• mellisonant
• Mellivora
• Mellivora capensis
• Mellon
• mellow
• mellow out
• mellowed
• mellowing
• mellowingly
• mellowly
• mellowness
• Melocactus
• melodeon
• melodic
• melodic line
• melodic phrase
• melodic theme
• melodically
• melodious
• melodiously
• melodiousness
• melodise
• melodist
• melodize