1. Cobalt, as in the metallic element, comes from kobold, a goblin-like creature from German folklore (familiar to Dungeons & Dragons fans). Cobalt miners used to die from the arsenic in cobalt ore, which was blamed on the kobolds.
2. Pandemonium was a term invented by John Milton in Paradise Lost. It referred to a great city in Hell, and means "place of all the demons".
3. Walrus is a corruption, via Dutch, of Old Norse words meaning "whale-horse".
4. Casino means "little house" in Italian. It didn't come to mean "gambling house" until the mid-19th century.
5. Adder, umpire and apron used to start with an N (nadder, numpire, napron). They lost the N in the early Middle Ages, because people kept mishearing them as "an adder" and so on. (Newt and nickname gained their Ns the same way: They were originally "an eute" and "an eke-name").
6. Noon comes from novem, the Latin for "ninth", and meant the ninth hour of the day – which, by the Roman reckoning, was what we now call 3pm. It's not clear why it moved by three hours.
7. Trivia comes from the plural of the Latin word trivium, meaning a place where three roads come together. Quadrivium meant a crossroads.
8. Treadmills were once a punishment, not gym equipment: Victorian prisoners powered a huge mill which crushed corn or rocks.
9. Dumbbells were originally ropes with weights on, rather than bars. They looked like the ropes used to ring church bells, hence "dumb (silent) bells".
10. Checkmate comes from shah mat, Arabic for "the king is dead".
11. Second, as in one-60th of a minute, comes from secunda pars minuta, the second diminished part. Originally the hour was divided into sixty parts once – creating prima pars minuta, the first diminished part, or "prime minute" – and then divided again, for the secunda pars minuta, or "second minute". Those names were shortened to "minute" and "second".
12. Moment comes from the Latin for movement – momentum – and meant the smallest weight that would move the pointer on a scale. Later it came to apply to a small amount of time, as well, and in the 13th century was defined as one-40th of an hour.
13. Bumph, meaning "Useless or tedious printed material", comes from military slang for toilet paper ("bum-fodder").
14. Penguin may come from the Welsh for "white head" (pen, "head", gwyn, "white"), and originally referred to the great auk, a now-extinct bird which lived in the north Atlantic.
15. Whisky comes from the Gaelic word uisgebeatha, meaning "water of life".
16. Vodka means "little water" in Russian.
17. Tory comes from an Irish word for "outlaw". In 1679 it was used as a slur by the Whig party to opponents of a bill they supported. When those opponents formed their own party, the name stuck.
18. Cloud comes from clud, an Old English word for "rock".
19. Girl comes from gyrle, a Middle English word meaning "child" or "youth", and applied to both sexes. In The Canterbury Tales, Chaucer talks about the "yonge gyrles of the diocise", meaning the young children of the diocese.
20. Quarantine comes from the Latin for "forty", and originally referred to Jesus's 40 days in the desert. Later it came to mean the length of time widows were allowed to stay in the home of their deceased husband, and later still a medical quarantine for ships which were feared to carry the plague.
21. Salad means "salted", and comes from the Latin herba salata, salted herbs.
22. Supercilious comes from the Latin for eyebrow, supercilium, which supercilious people often raise.
23. Freelancer originally referred to mercenary knights ("free lances") who would fight for any side willing to pay them. The word first appears in Sir Walter Scott's Ivanhoe.
24. Bully comes from the Dutch for "brother", and was originally a term of endearment.
25. Fuck is first recorded in a part-Latin poem from 1475.
26. Sahara desert (Arabic) means "desert desert"; Gobi desert (Mongolian) means "desert desert"; Mississippi river (Algonquin) means "big river river"; La Brea tar pits (Spanish) means "the tar tar pits"; and Torpenhow hill, in Cumbria, seems to come from Norse, Old English, Welsh and modern English components meaning "hill hill hill hill".
27. Alcove, algebra, coffee, cotton, ghoul, mascara and zero are all derived from Arabic words.
28. Parasite is from the Ancient Greek for "eating beside", and referred to people who ate at someone else's table.
29. Disaster comes from the Latin for "ill star" ("aster" as in asteroid or asterisk).
30. Torpedo means "stingray" in Latin.
31. Translation originally referred to the practice of exhuming a saint and moving his or her body elsewhere.
32. Ytterbium, yttrium, erbium and terbium, the chemical elements, are all named after the little Swedish village Ytterby, near Stockholm.
33. Rebarbative, barber and Barbados all come from the Latin for "beard".
34. Apostrophe means "turning away" in Ancient Greek.
35. George, the name, means "earth-worker" in Ancient Greek. It derives from the same root as geographer and geologist.
36. Bootlegging comes from the practice of 19th-century alcohol smugglers hiding bottles in their boots.
37. Berk comes from Cockney rhyming slang. It's short for "Berkshire hunt", meaning "cunt".
38. Pedant, which derives from Old French, used to mean "schoolteacher".
39. Jinx, as in a curse of bad luck, comes from an Old English name for a woodpecker-like bird called the wryneck.
40. Ostrich derives from the Ancient Greek for "big sparrow".
41. Oxymoron derives from the Greek words for "sharp" and "dull", and is therefore itself an oxymoron.
42. Booze, as in alcohol, derives from the 14th century. The earliest known reference is (probably) from an Old English ballad, the first line of which goes "Drynke to hym deorly of fol god bous" ("Drink to him dearly with full, good booze").
43. Hilary comes from the same root as hilarious and means "cheerful".
44. Mortgage is from the French for "death contract".
45. Chicago seems to come from a Native American word meaning "wild onion".
46. Album comes from the Latin for "white" and used to refer to a blank tablet.
Taken from Word Drops: A Sprinkling of Linguistic Curiosities by Paul Anthony Jones, published by Elliott & Thompson £11.99 hb or ebook.