Large Aquatic Mammal, Also Called a Sea Cow
Puzzle 9 of The Moon Hard Pack
Question is: Large Aquatic Mammal, Also Called a Sea Cow
and the answer is: MANATEE
Word Meaning:
MANATEE — A mostly herbivorous sirenian of the genus Trichechus, having a paddle-like tail and nails on their flippers, found in tropical regions.
Definitions from Wiktionary.