1. 河口：osteocolla 多孔石灰华 | ostiary 河口 | ostracoda 介形类
2.
2. 看门人：osteotomy 切骨术 | ostiary 看门人 | ostiole 小孔
noun
1. someone who guards an entrance
Synonym: doorkeeperdoormandoor guardhall porterportergatekeeper
2. the lowest of the minor Holy Orders in the unreformed Western Church but now suppressed by the Roman Catholic Church
Synonym: doorkeeperostiarius