spicule

noun

spic·​ule ˈspi-(ˌ)kyül 

1

: a slender pointed usually hard body

especially : one of the minute calcareous or siliceous bodies that support the tissue of various invertebrates (such as sponges)

2

: a spikelike short-lived prominence appearing close to the chromosphere of the solar atmosphere

spicular

ˈspi-kyə-lər 

adjective

spiculation

ˌspi-kyə-ˈlā-shən 

noun

Examples of spicule in a Sentence

Recent Examples on the Web

Using scanning electron microscope analysis, the team observed differences in dorsal spicules on the shell. — Hanna Wickes, Miami Herald, 3 Mar. 2026

Researchers observed differences in dorsal spicules, tiny thorn-like projections on the animal’s back. — Hanna Wickes, Kansas City Star, 3 Mar. 2026

Scanning electron microscope analysis showed that the dorsal spicules on the shell were rounded rather than pointed. — Hanna Wickes, Charlotte Observer, 3 Mar. 2026

Right now, the skin-care industry is brimming with exciting, often mysterious, active ingredients—think exosomes, spicules, and PDRN. — Deanna Pai, Vogue, 23 Feb. 2026

Word History

Etymology

New Latin spicula & Latin spiculum; New Latin spicula, alteration of Latin spiculum head of a spear or arrow, diminutive of spicum, spica ear of grain

First Known Use

1785, in the meaning defined at sense 1

Kids Definition

spicule

noun

spic·​ule ˈspik-yü(ə)l 

: a small hard needlelike structure

especially : one of the tiny calcium- or silica-containing bodies that support the tissues of various invertebrates and especially sponges

Medical Definition

spicule

noun

spic·​ule ˈspik-(ˌ)yü(ə)l 

: a minute slender pointed usually hard body (as of bone)