simpleminded

US: /ˈsɪmpəlˈmaɪndɪd/ ,(sim′pəl mīn′did, -mīn′-)

WordReference Random House Learner's Dictionary of American English © 2026

sim•ple•mind•ed or sim•ple-mind•ed /ˈsɪmpəlˈmaɪndɪd/   adj. 

1. lacking in mental sharpness.
2. lacking in complex thought:
   a simple-minded solution to a complicated problem.
3. mentally weak;
   feeble-minded.

WordReference Random House Unabridged Dictionary of American English © 2026

sim•ple•mind•ed  (sim′pəl mīn′did, -mīn′-), adj. 

1. free of deceit or guile;
   artless or unsophisticated.
2. lacking in mental acuteness or sense.
3. mentally deficient. Also, sim′ple-mind′ed. 

• simple + minded 1735–45

sim′ple•mind′ed•ly, adv. 
sim′ple•mind′ed•ness, n. 
Synonyms

• 2, 3. . stupid, foolish, slow, dull-witted, half-witted.

Collins Concise English Dictionary © HarperCollins Publishers::

simple-minded adjective

1. lacking intelligence
2. unsophisticated; artless

ˌsimple-ˈmindedly adverb

ˌsimple-ˈmindedness noun