Mistreat comes from the Latin prefix mis‑ meaning “wrongly” combined with the Old French verb traiter, itself from Latin tractare “to handle”. The compound entered English in the late 16th century, originally meaning “to handle or deal with badly”. Today it denotes cruelty or neglect toward a person or thing.
“Assassin” comes from the Arabic hashshashin — the plural of hashshash (hashish user) — a name applied to members of the Nizari Ismaili sect of medieval Islam, whose fighters were feared for targeted political killings. The name was recorded by Crusaders and travelers including Marco Polo, who associated the sect with the drug. The Arabic plural became the medieval Latin assassinus and entered European languages through Italian and French.
“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.
“Dunce” comes from the name of John Duns Scotus (c. 1265–1308), one of the most brilliant philosophers of the Middle Ages. Renaissance humanists mocked his followers — the “Dunses” or “Dunsmen” — as obstinate pedants clinging to an outdated system. The name of a philosopher celebrated for intellectual subtlety became, through this reversal of reputation, a word for a stupid person.
“Hazard” comes from the Arabic az-zahr (the dice — literally “the flower,” from the markings on dice). The word entered Spanish as azar (chance, accident) and then Old French as hasard — a dice game that Crusaders learned in the Middle East and brought back to Europe. The dice game became a general term for chance, and chance became a term for risk.
“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).
The word “salary” comes from the Latin word salarium, derived from sal meaning “salt.” Roman soldiers were reputedly given an allowance of salt or money to buy salt — a precious commodity in the ancient world. The word entered English in the 14th century via Old French salaire.
The word “muscle” comes from the Latin musculus, meaning “little mouse.” Romans noticed that muscles moving under the skin resembled a mouse running beneath a cloth — the bulging and rippling motion reminded them of a small rodent. The word entered English in the 15th century via Latin.
The word “nice” has undergone one of the most dramatic semantic shifts in the English language. It originally meant “foolish” or “ignorant” in the 13th century, derived from Latin nescius meaning “ignorant.” Over seven centuries, its meaning shifted through “lascivious,” “extravagant,” “fastidious,” and “precise” before arriving at today’s sense of “pleasant” or “kind.”