humdinger (n.)

"something superlative," 1809, American English, agent noun from ding (v.). Baseball sense of "a home run" is by 1984.

c. 1600, of insects, agent noun from hum (v.). Meaning "energetic person or thing" is 1680s; that of "excellent person or thing" is slang from 1907. As short for Humvee, attested from 1983.