1. Not easily perturbed or excited or upset; marked by extreme calm and composure
   "hitherto imperturbable, he now showed signs of alarm"; "an imperturbable self-possession"
   - unflappable

See also: composed, imperturbableness

• acronymous
• acropetal
• acrophobia
• acrophobic
• acrophony
• acropolis
• Acropora
• acroscopic
• acrosome
• across
• across the country
• across the nation
• across-the-board
• acrostic
• Acrostichum
• Acrostichum aureum
• acrotic
• acrylamide
• acrylate
• acrylate resin
• acrylic
• acrylic acid
• acrylic fiber
• acrylic paint
• acrylic resin