Word Origin & History
frumpy
1746, "cross-tempered," from frump (n.) "bad temper" (1668) and an earlier v. meaning "to mock, browbeat" (1553), of obscure origin, perhaps imitative of a sneer or derisive snort. Sense of "sour-looking, unfashionable" is from 1825, but this may be a shortening of frumple "to wrinkle, crumple" (1398), from M.Du. verrompelen, from ver- "completely" + rompelen "to rumple." Frump "shabby, unstylish woman" is from 1817.