† polyacanthousadj.
Origin: A borrowing from Latin, combined with an English element. Etymons: Latin polyacanthus  , -ous suffix.
Etymology:  <  scientific Latin polyacanthus (1827 or earlier as specific epithet in botanical use;  <  poly-  poly- comb. form   + ancient Greek ἄκανθα   spine, thorn: see acanthus n.) + -ous suffix. Compare scientific Latin Polyacanthus   (1769 or earlier), Polyacantha   (1844 or earlier), genus names of plants, and also classical Latin polyacanthos   a kind of thistle (Pliny), Hellenistic Greek πολυάκανθος   welted thistle (Theophrastus). Compare pentacanthous adj. at penta- comb. form 1, oligacanthous adj. at oligo- comb. form , myriacanthous adj. at myria- comb. form 2, etc.
 Botany. 
Obsolete. 
rare.
1858    R. G. Mayne  		(1860)	 994/1  				Polyacanthus, having many spines or thorns, as the Melocactus polyacanthus: polyacanthous.
 This entry has been updated (OED Third Edition, September 2006; most recently modified version published online March 2020).