The Collaborative International Dictionary
hand-hole
hand-hole \hand"-hole`\ (h[a^]nd"h[=o]l`), n. (Steam Boilers) A small hole in a boiler for the insertion of the hand in cleaning, etc.
Hand-hole plate, the cover of a hand-hole.
Wiktionary
hand-hole
n. ''(Steam Boilers):'' A small hole in a boiler for the insertion of the hand in cleaning, etc.