to be officially weighed before competing in a sport, especially boxing or horse racing

Tyson weighed in at 245 lb for the fight. 泰森打这场比赛时体重为245磅。

to become involved in an argument or discussion in a forceful way

Several leading architects weighed in with criticisms regarding the design of the new museum. 几位著名的建筑师加入讨论，对新博物馆的设计方案提出了批评意见。