lock filling and emptying opening
/ˈlɒk ˈfɪlɪŋ and ˈɛmptiɪŋ ˈəʊpənɪŋ/
n
English · lock filling and emptying opening中文 · 船闸充泄水孔Español · abertura de llenado y vaciadoFrançais · pertuis de remplissage et de vidange
意味：Holes through which the water flows in to fill the lock-chamber or out to empty it.