舷窓 is read as げんそう (gensou) and means porthole.
げんそう
gensou
まど
window
てんそう
head
しゃそう
train window
どうそう
being a graduate of the same school
でまど
bay window
はりだしまど
てんぼうまど
observation window
れんじまど
lattice window
あげさげまど
double-hung window
にじゅうまど
double-glazed window
せいえんそう
round window
けんさくまど
search box