think (v.)

Old English þencan "imagine, conceive in the mind; consider, meditate, remember; intend, wish, desire" (past tense þohte, past participle geþoht), probably originally "cause to appear to oneself," from Proto-Germanic *thankjan (source also of Old Frisian thinka, Old Saxon thenkian, Old High German denchen, German denken, Old Norse þekkja, Gothic þagkjan).

Old English þencan is the causative form of the distinct Old English verb þyncan "to seem, to appear" (past tense þuhte, past participle geþuht), from Proto-Germanic *thunkjan (source also of German dünken, däuchte). Both are from PIE *tong- "to think, feel" which also is the root of thought and thank.

The two Old English words converged in Middle English and þyncan "to seem" was absorbed, except for its preservation in archaic methinks "it seems to me."

As a noun, think, "act of prolonged thinking," is attested by 1834. The figurative thinking cap is attested from 1839.

updated on August 16, 2018

Definitions of think from WordNet
think (v.)
judge or regard; look upon; judge;
I think that he is her boyfriend
I think he is very smart
Synonyms: believe / consider / conceive
think (v.)
expect, believe, or suppose;
I thought to find her in a bad state
he didn't think to find her in the kitchen
Synonyms: opine / suppose / imagine / reckon / guess
think (v.)
use or exercise the mind or one's power of reason in order to make inferences, decisions, or arrive at a solution or judgments;
I've been thinking all day and getting nowhere
Synonyms: cogitate / cerebrate
think (v.)
recall knowledge from memory; have a recollection;
I can't think what her last name was
Synonyms: remember / retrieve / recall / call back / call up / recollect
think (v.)
imagine or visualize;
Just think--you could be rich one day!
think (v.)
focus one's attention on a certain state;
think thin
think (v.)
have in mind as a purpose;
She didn't think to harm me
We thought to return early that night
Synonyms: intend / mean
think (v.)
decide by pondering, reasoning, or reflecting;
Can you think what to do next?
think (v.)
ponder; reflect on, or reason about;
think (v.)
dispose the mind in a certain way;
Do you really think so?
think (v.)
have or formulate in the mind;
think (v.)
be capable of conscious thought;
Man is the only creature that thinks
think (v.)
bring into a given condition by mental preoccupation;
She thought herself into a state of panic over the final exam
think (n.)
an instance of deliberate thinking;
I need to give it a good think
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