astroid, a. and n.
(ˈæstrɔɪd)
[f. Gr. ἀστροειδής star-like, f. ἀστήρ star: see -oid.]
A. adj. Star-shaped, star-like (cf. asteroid a.).
| 1909 in Webster. |
B. n. Geom. A hypocycloid with four cusps.
| 1897 H. Lamb Infinit. Calculus ix. §138 The ‘four-cusped hypocycloid’..is sometimes called the ‘astroid’. |