- cheerful (adj.)
[cheerful 词源字典]
- c. 1400, "full of cheer," from cheer (n.) + -ful. Meaning "elevating the spirits" is from mid-15c. Related: Cheerfully; cheerfulness.[cheerful etymology, cheerful origin, 英语词源]
- chirpy (adj.)
- "cheerfully perky," 1825, from chirp + -y (2). The notion is perhaps of birds fluttering and chattering.