Decagon comes from ancient Greek δεκάγωνον (dekágōnon), literally “ten‑angles.” The term passed through Latin decagonus and medieval French before appearing in English in the late 1300s. It has always referred to a ten‑sided geometric figure.
The verb *deliquesce* comes from Latin *deliquēscere*, meaning “to melt or become liquid.” It entered English in the early 17th century, first used by chemists describing salts that absorb moisture and turn into liquid. The word carries the same core idea of a solid giving way to fluidity.
Formicant comes from Latin *formica* “ant” plus the adjectival suffix –ant, originally meaning “pertaining to ants”. It entered English in the early 19th century via scientific French to describe substances derived from ant secretions, especially formic acid. Today it is used chiefly in chemistry and entomology.
“Disaster” comes from the Italian disastro — a compound of dis- (bad, against) and astro (star, from Latin astrum). Literally, a “bad star” — reflecting the Renaissance belief that the positions of stars governed human fate. An unfavorable stellar alignment was a disaster: celestial catastrophe written in the sky before it happened on earth.
“Muscle” comes from Latin musculus, meaning “little mouse.” Roman anatomists observed that a flexing muscle beneath the skin looks like a small mouse running — the bicep rippling under the arm resembles a mouse’s back moving. The same Latin word musculus also gave us “mussel,” because the shellfish’s dark, curved shape resembles a mouse.
“Calculate” comes from Latin calculare, itself from calculus meaning “small stone” or “pebble.” Romans used pebbles on counting boards to perform arithmetic, and the act of moving stones became the word for computation. The same Latin word gave mathematicians the term “calculus” (Newton’s system of infinitesimal calculation) and geologists “calcium” (from calx, limestone — the parent of calculus).