the word 'spicule' is a direct borrowing from latin 'spicula', the diminutive form of 'spica', meaning 'a small sharp point' or 'a little ear of grain'. the root 'spica' itself is thought to be of proto-indo-european origin, related to the concept of a sharp point or a head, as seen in an ear of grain. this literal sense of a small, pointed object was adopted into scientific english in the 18th century to describe fine, needle-like structures in organisms like sponges and later in astronomy for jet-like features on the sun. the logic of the word perfectly captures its modern meaning: a diminutive ('-ule') form of a point ('spic').

Structure: spic (point) + ule (small diminutive suffix) spic is from latin 'spica' meaning 'ear of grain, point'. ule is a latin diminutive suffix '-ulus', '-ula', '-ulum', indicating something small.