n. 1
The careful consideration of multiple factors; deliberation.
After much thought, I have decided to stay.
n. 2
A representation created in the mind without the use of one's faculties of vision, sound, smell, touch, or taste; an instance of thinking.
I hate the thought of going back to work Monday morning.
n. 3
The operation by which mental activity arise or are manipulated; the process of thinking; the agency by which thinking is accomplished.
The only reason some people get lost in thought is because it’s unfamiliar territory.
n. 4
A way of thinking (associated with a group, nation, region or idea).
Traditional eastern thought differs markedly from that of the west.

Related words

Word family: thoughtcasting thoughtful thoughtless thought-provoking thoughty
Phrases: thought process train of thought chain of thought school of thought food for thought line of thought thought control thought path

Forms

Thought or Reason?

Thought, the act, process, or power of thinking, is often used to denote the thinking faculty, and especially the reason.

J. C. Fernald, English Synonyms and Antonyms (1914)

Use in printed books, per decade from 1850 to 2019.

3 letters: bit¹, dab¹, jot¹
4 letters: care¹, head¹, mind¹, idea³, view¹, hint¹, dash¹, lick¹, whit¹
5 letters: touch¹, trace¹, spark¹
6 letters: design², notion², trifle², musing²
7 letters: opinion³, concept², concern², conceit²
8 letters: thinking², judgment²
9 letters: intention³, sentiment³, reasoning³, judgement², pondering³, scintilla³, mentation, ideolatry
10 letters: conclusion³, reflection³, meditation⁴, conception³, persuasion³, sprinkling², smattering³, rumination⁴, solicitude⁴, cogitation⁴
11 letters: imagination⁵, speculation⁴, supposition⁴, cerebration
12 letters: deliberation⁵, intellection
13 letters: consideration⁵, contemplation⁴

The small number after each word is its number of syllables (idea³ = 3 syllables).