“+ adjective
1. : not taking thought : heedless , inattentive , unmindful
an exploit performed thousands of times a day by unthinking New Yorkers — Bennett Cerf
2. : not indicating thought or reflection : vacant
with earnest eyes, and round unthinking face — Alexander Pope
3. : not having the power of thought
vicious unthinking animal — Richard Sale
• un·think·ing·ly adverb
• un·think·ing·ness noun