type of tall herb or shrub native to the Mediterranean regions, 1660s, from Latin acanthus, name of the plant, from Greek akanthos, from ake "point, thorn" (from PIE root *ak- "be sharp, rise (out) to a point, pierce") + anthos "flower" (see anther). So called for its large spiny leaves. A conventionalized form of the leaf is used in Corinthian capitals. Related: Acanthaceous.
before vowels, cephal-, word-forming element meaning "head, skull, brain," Modern Latin combining form of Greek kephalē "head, uppermost or top part, source," from PIE *ghebh-el- (source also of Tocharian spal "head;" Old High German gebal "skull;" also, via the notion of "front," Gothic gibla, Old Norse gafl "side of a facade").
<a href="https://www.etymonline.com/word/acanthocephalous">Etymology of acanthocephalous by etymonline</a>
Harper, D. (n.d.). Etymology of acanthocephalous. Online Etymology Dictionary. Retrieved $(datetime), from https://www.etymonline.com/word/acanthocephalous