EnglishMerriam-Webster Dictionary
2 free from emotional or mental agitation //bystanders tried to help the injured person remain calm while they waited for the ambulance to arrive collected, composed, cool, coolheaded, equal, level, limpid, peaceful, placid, possessed, recollected, sedate, self-composed, self-possessed, serene, smooth, together, tranquil, undisturbed, unperturbed, unruffled, unshaken, untroubled, unworried 2 free from emotional or mental agitation //bystanders tried to help the injured person remain calm while they waited for the ambulance to arrive collected, composed, cool, coolheaded, equal, level, limpid, peaceful, placid, possessed, recollected, sedate, self-composed, self-possessed, serene, smooth, together, tranquil, undisturbed, unperturbed, unruffled, unshaken, untroubled, unworried 2 free from emotional or mental agitation //bystanders tried to help the injured person remain calm while they waited for the ambulance to arrive collected, composed, cool, coolheaded, equal, level, limpid, peaceful, placid, possessed, recollected, sedate, self-composed, self-possessed, serene, smooth, together, tranquil, undisturbed, unperturbed, unruffled, unshaken, untroubled, unworried 2 free from emotional or mental agitation //bystanders tried to help the injured person remain calm while they waited for the ambulance to arrive collected, composed, cool, coolheaded, equal, level, limpid, peaceful, placid, possessed, recollected, sedate, self-composed, self-possessed, serene, smooth, together, tranquil, undisturbed, unperturbed, unruffled, unshaken, untroubled, unworried