duller

English

Etymology

dull +‎ -er

Adjective

duller

1. comparative form of dull: more dull

Noun

duller (plural dullers)

1. One who, or that which, dulls.
   • Beaumont and Fletcher

     But, of all, your grace must fly phlebotomy, fresh pork, conger, and clarified whey: they are all dullers of the vital spirits.