[big-hed, -hed]
See more synonyms for bighead on
  1. Informal. an excessive estimate of one's importance; conceit.
  2. Veterinary Pathology.
    1. an inflammatory swelling of the tissues of the head of sheep, caused by the anaerobic bacillus Clostridium novyi.
    2. enlargement of the head and jawbones of horses resulting from nutritional hyperthyroidism.

Origin of bighead

An Americanism dating back to 1795–1805; big1 + head
Related formsbig·head·ed, adjectivebig·head·ed·ness, noun Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018

British Dictionary definitions for bigheaded


  1. informal a conceited person
  2. US and Canadian informal conceit; egotism
  3. vet science
    1. an abnormal bulging or increase in the size of an animal's skull, as from osteomalacia
    2. any of various diseases of sheep characterized by swelling of the head, esp any caused by infection with Clostridium bacteria
Derived Formsbigheaded, adjectivebigheadedly, adverbbigheadedness, noun
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012