gavel

gavel
/ˈgævl; `ɡævl/ n
small hammer used by an auctioneer or chairman as a signal for order or attention （拍卖者或主席用的）小槌
    bang, rap, etc one's gavel on the table 用小槌在桌上猛击、 敲打等.

牛津英汉双解词典