interspinal Syllabification: (in·ter·spi·nal)Pronunciation: /ˌintərˈspīnl/Definition of interspinal adjective Anatomy situated between the spines or spinous protuberances of the vertebrae. Derivatives interspinousPronunciation: /-ˈspīnəs/ adjective interspinal in other Oxford dictionaries Definition of interspinal in the British & World English dictionary