sighthole

n. (测量用仪器等上的)观察孔,检查孔,窥视孔

词形变化

sightholes 复数 sightholes

释义与例句

n.
  1. 1.

    An eyehole in a furnace, a boiler, etc.

词源

From sight + hole.

来源：wiktionary