- clueless (adj.)
[clueless 词源字典]
- 1862, "trackless," from clue (n.) + -less. Meaning "ignorant, uninformed" is from 1943, said to be RAF slang from 1930s. Student slang use by 1985 is perhaps an independent extension along the same line. Related: Cluelessly; cluelessness.[clueless etymology, clueless origin, 英语词源]