1 [U] a situation in which there is a lot of action or movement 繁忙的活动;热闹:
The house was full of activity on the morning of the wedding.举行婚礼的那个早上,房子里很热闹。 [OPP] inactivity 反义词为 inactivity
2 [C] something that you do, usually regularly and for enjoyment 所做的事(多指经常的和为消遣的):
The hotel offers a range of leisure activities.这家饭店提供许多休闲活动。☞Look at the note at act ². 参看act^2的注释。