keelson
keelson[ˈkiːls(ə)n](亦作 kelson)noun- a structure running the length of a ship and fastening the timbers or plates of the floor to its keel
内龙骨
语源- Middle English kelswayn, related to Low German kielswīn, from kiel 'keel of a ship' + swīn 'swine' (used as the name of a timber)
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