WordReference Random House Unabridged Dictionary of American English © 2025
knuck′le ball′, [Baseball.]
- Sporta slow pitch that moves erratically toward home plate, usually delivered by holding the ball between the thumb and the knuckles of the first joints of the first two or three fingers.
- 1905–10, American.
'knuckle ball' also found in these entries (note: many are not synonyms or translations):