“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).
“Candidate” comes from Latin candidatus, meaning “clothed in white.” In ancient Rome, those seeking public office wore a toga candida — a toga whitened with chalk — to signal their openness and purity to voters. The gleaming white garment was a visual appeal for trust. The same Latin root gives us “candid” (frank, white = pure), “candor,” “candle,” and “incandescent.”
“Panic” comes from Greek Panikos (of Pan), named for Pan — the Greek god of the wilderness, flocks, and rustic music. Pan was believed to cause sudden, irrational terror in travellers who disturbed him in lonely places, particularly at noon when he was thought to sleep. The adjective panikos (of Pan) became the noun describing the sudden, uncontrollable fear he caused.
“Tragedy” comes from ancient Greek tragodia — a compound of tragos (goat) and ode (song) — literally “goat song.” Why a goat? Several theories exist: a goat was the prize in early dramatic competitions; actors wore goat-skin costumes; the chorus performed at a ceremony involving a goat sacrifice. The precise reason is debated, but the word is one of the most richly mysterious etymologies in the arts.
“Companion” comes from Late Latin companio — literally “one who shares bread” — from com- (together, with) + panis (bread). In a world where sharing a meal was a bond of loyalty and trust, the word for a trusted fellow was built from the act of breaking bread together. The same “panis” root gives us company, accompany, pantry, and the French surname “Dupain” (of the bread).