worthless (adj.)

Old English weorþ "value, price, price paid; worth, worthiness, merit; equivalent value amount, monetary value," from worth (adj.). From c. 1200 as "excellence, nobility."

word-forming element meaning "lacking, cannot be, does not," from Old English -leas, from leas "free (from), devoid (of), false, feigned," from Proto-Germanic *lausaz (cognates: Dutch -loos, German -los "-less," Old Norse lauss "loose, free, vacant, dissolute," Middle Dutch los, German los "loose, free," Gothic laus "empty, vain"), from PIE root *leu- "to loosen, divide, cut apart." Related to loose and lease.

"having a value beyond price, invaluable," 1590s, from price (n.) + -less. Compare worthless, which has the opposite sense. Colloquial sense of "delightful, amusing" is attested from 1907. Related: Pricelessly; pricelessness.