acetabulum acetabulous • acetacetic · · · Info · Definitions · Synonyms · Characters · · acetabulum · · Text Latin · · Script 10 · · Length 5 · · Syllables Definitions · · · (noun) the cup-shaped hollow in the hipbone into which the head of the femur fits to form a ball-and-socket joint. Synonyms: cotyloid cavity. · · Noun Definition 1 Synonyms · · · cotyloid cavity · · Synonym 1 Characters · · a latin small letter a U+0061 b latin small letter b U+0062 c latin small letter c U+0063 e latin small letter e U+0065 l latin small letter l U+006C m latin small letter m U+006D t latin small letter t U+0074 u latin small letter u U+0075