cartilaginous fishes having horizontally flattened bodies and enlarged winglike pectoral fins with gills on the underside; most swim by moving the pectoral fins | a sharp rigid animal process or appendage; as a porcupine quill or a ridge on a bone or a ray of a fish fin |
any of the stiff bony spines in the fin of a fish | the part of a book's cover that encloses the inner side of the book's pages and that faces outward when the book is shelved |
the syllable naming the second (supertonic) note of any major scale in solmization | the series of vertebrae forming the axis of the skeleton and protecting the spinal cord |
a column of light (as from a beacon) | a small sharp-pointed tip resembling a spike on a stem or leaf |
a group of nearly parallel lines of electromagnetic radiation | any sharply pointed projection |
a branch of an umbel or an umbelliform inflorescence | |
(mathematics) a straight line extending from a point | |