Armadillo is Spanish and means "little armoured one" — armado, "armoured," with the diminutive ending -illo, from Latin armare, "to arm, to furnish with weapons," from arma, which meant tools and implements of war including defensive armour. The animal is named for its plated shell.
The double l is a Spanish spelling that English borrowed without borrowing the sound behind it: in Spanish that ll is its own letter with its own value, and English simply reads it as a doubled l. The same happens in guerrilla, tortilla and vanilla. The -o ending and the ll together make a fairly reliable pair of Spanish markers. English took the word in the 1570s, along with a good deal of other vocabulary for American animals and plants that reached the language through Spanish explorers.
armadillo (n.) burrowing mammal of the American tropics, 1570s, from Spanish armadillo , diminutive of armado "armored," from Latin armatus , past participle of armare "to arm, furnish with weapons," from arma "weapons" (including defensive armor), literally "tools, implements (of war);" see arm (n.2). The animal is so called for its hard, plated shell. also from 1570s
armadillo came in through Later and wider borrowings, and its spelling follows that family's conventions.
How that family writes these sounds
| a rolled or doubled liquid in a Spanish loan | ll, rrguerrilla, armadillo |
What gives it away on the page
| -o/-a endings, ll, rr, ny for ñ | Spanish — much of it from the Americas.tornado, cargo, plaza, armadillo, guerrilla, canyon, mosquito |
Later and wider borrowings in the spelling guide · guess another word's family