thoughtless; heedless; inconsiderate: an unthinking, tactless person.
indicating lack of thought or reflection: a dull, unthinking expression on his face.
not endowed with the faculty of thought: unthinking matter.
not exercising thought; not given to reflection: This book will not profit an unthinking person.
not thinking; unmindful: chores done in an unthinking manner.

Nearby words

  1. unthankful,
  2. unthatch,
  3. unthaw,
  4. unthink,
  5. unthinkable,
  6. unthought,
  7. unthought-of,
  8. unthread,
  9. unthrifty,
  10. unthrone

Origin of unthinking

First recorded in 1670–80; un-1 + thinking

Related formsun·think·ing·ly, adverbun·think·ing·ness, noun



verb (used without object), un·thought, un·think·ing.

to end one's thought or reverse the process of thought.

verb (used with object), un·thought, un·think·ing.

to dispel from the mind: Unthink your thoughts.

Origin of unthink

First recorded in 1590–1600; un-2 + think1

Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Examples from the Web for unthinking

British Dictionary definitions for unthinking



lacking thoughtfulness; inconsiderate
heedless; inadvertentit was done in an unthinking moment
not thinking or able to think
Derived Formsunthinkingly, adverbunthinkingness, noun


verb -thinks, -thinking or -thought (tr)

to reverse one's opinion about
to dispel from the mind
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

Word Origin and History for unthinking



"unreflecting," 1670s, from un- + present participle of think.

Online Etymology Dictionary, © 2010 Douglas Harper