thoughtful (adj.)youdaoicibaDictYouDict[thoughtful 词源字典]
c. 1200, "contemplative, occupied with thought," from thought + -ful. Also in Middle English, "prudent; moody, anxious." Meaning "showing consideration for others" is from 1851 (compare thoughtless.) Related: Thoughtfully; thoughtfulness.[thoughtful etymology, thoughtful origin, 英语词源]