arrant

UK: /ˈærənt/ US: /ˈærənt/ ,(ar′ənt)

WordReference Random House Learner's Dictionary of American English © 2025

ar•rant /ˈærənt/   adj. [before a noun]

1. (used to emphasize something negative) complete;
   thorough;
   absolute:
   an arrant fool; arrant nonsense.

WordReference Random House Unabridged Dictionary of American English © 2025

ar•rant  (ar′ənt), adj. 

1. downright;
   thorough;
   unmitigated;
   notorious:
   an arrant fool.
2. wandering;
   errant.

• Middle English, variant of errant 1350–1400

ar′rant•ly, adv. 
Synonyms

• 1. . thoroughgoing, utter, confirmed, flagrant.

Collins Concise English Dictionary © HarperCollins Publishers::

arrant / ˈærənt/ adjective

1. utter; out-and-out: an arrant fool

Etymology: 14th Century: a variant of errant (wandering, vagabond); sense developed from its frequent use in phrases like arrant thief (hence: notorious)

ˈarrantly adverb