double comparative; see worse + -er (2). Attested from late 15c. and common 16c.-17c. Noun worsers "(one's) inferiors" is from 1580s.
Entries linking to worser
worse adj.
Old English wiersa, wyrsa "worse," from Proto-Germanic *wers-izon- (source also of Old Saxon wirs, Old Norse verri, Swedish värre, Old Frisian wirra, Old High German wirsiro, Gothic wairsiza "worse"), comparative of PIE *wers- (1) "to confuse, mix up" (source also of Old High German werra "strife," Old Saxon werran "to entangle, compound;" see war (n.)). Used as a comparative of bad, evil, ill or as the opposite of better. The adverb is Old English wyrs; the noun is Old English wyrsa. Phrase for better or for worse is attested from late 14c. (for bet, for wers); to change for the worse is recorded from c. 1400.
-er 2
comparative suffix, from Old English -ra (masc.), -re (fem., neuter), from Proto-Germanic *-izon (cognates: Gothic -iza, Old Saxon -iro, Old Norse -ri, Old High German -iro, German -er), from PIE *-yos-, comparative adjective suffix. Originally also with umlaut change in stem, but this was mostly lost in Old English by historical times and has now vanished (except in better and elder).
For most comparatives of one or two syllables, use of -er seems to be fading as the oral element in our society relies on more before adjectives to express the comparative; thus prettier is more pretty, cooler is more cool [Barnhart].