Definition from Wiktionary, the free dictionary
thinko (plural thinkos)
- (slang, neologism) A careless mistake made in thinking.
- I must have done quite a thinko, but I don't remember leaving my keys in the refrigerator.
- (a mistake): blooper, blunder, boo-boo, brain fart, defect, error, fault, faux pas, fluff, gaffe, lapse, mistake, slip, stumble
- See also Wikisaurus:error