inconsiderate (adj.)youdaoicibaDictYouDict[inconsiderate 词源字典]
late 15c., "done thoughtlessly," literally "not properly considered," from Latin inconsideratus "headstrong, unadvised, thoughtless," from in- "not, opposite of" (see in- (1)) + consideratus (see consider). Related: Inconsiderately; inconsiderateness.[inconsiderate etymology, inconsiderate origin, 英语词源]