(a) (of the sea) without large waves; still （指海洋）无浪的, 平静的. (b) (of the weather) not windy （指天气）无风的: a calm, cloudless day 无风无云的一天. 
not excited, nervous or agitated; quiet; untroubled 镇定的; 安静的; 无忧虑的: It is important to keep/stay calm in an emergency. 在紧急情况下保持镇静是很重要的. * The city is calm again after yesterday's riots. 这座城市经过昨天的动乱以後又平静下来了. =>Usage at quiet 用法见quiet.> calm n [C, U]
1 calm condition or period 平静的状态或时期: the calm of a summer evening 夏日夜晚的宁静 * After the storm came a calm. 风暴过後, 万籁俱寂.
2 (idm 习语) the calm before the storm time of unnatural calm immediately before an expected outburst of violent activity, passion, etc 暴风雨前的平静（在预料到激烈的活动﹑ 情绪等即将爆发之前的反常的 平静时期）.
calm v [I, Ip, Tn, Tn.p] ~ (sb) (down) (cause sb to) become calm （使某人）平静, 镇静, 安静: Just calm down a bit! 你先静一静! * Have a brandy it'll help to calm you (down). 来点儿白兰地--能使你静下来.
calmly adv: He walked into the shop and calmly (ie impudently and self-confidently) stole a pair of gloves. 他走进商店若无其事地偷了一副手套.
calmness n [U].