QuellingThe TEEN's mother quelled his fears of the thunder. Origin of quell. Expand. Middle English · Old English. 900. before 900; Middle English quellen, Old English . .To put down forcibly; suppress: Police quelled the riot. 2. To pacify; quiet: finally quelled the TEENren's fears. [Middle English quellen, to kill, from Old English . Synonyms for quelling at Thesaurus.com with free online thesaurus, antonyms, and definitions. Dictionary and Word of the Day.