calm

sense 1: make calm or still; "quiet the dragons of worry and fear"
calm calm_down quiet tranquilize tranquillize tranquillise quieten lull still

sense 2: make steady; "steady yourself"
steady calm becalm

sense 3: become quiet or calm, esp. after a state of agitation; "After the fight both men need to cool off."; "It took a while after the baby was born for things to settle down again."
calm calm_down cool_off chill_out simmer_down settle_down cool_it

sense 4: cause to be calm or quiet as by administering a sedative to; "The patient must be sedated before the operation"
sedate calm tranquilize tranquillize tranquillise