"ground meat rolled up into a small ball," 1801, from meat + ball (n.1). As an insult to a person, by 1941.
Entries linking to meatball
meat n.
Middle English mēte, from Old English mete "food, nourishment, sustenance" (paired with drink), "item of food; animal food, fodder," also "a meal, repast," from Proto-Germanic *mati (source also of Old Frisian mete, Old Saxon meti, Old Norse matr, Old High German maz, Gothic mats "food," Middle Dutch, Dutch metworst, German Mettwurst "type of sausage"), from PIE *mad-i-, from root *mad- "moist, wet," also with reference to food qualities, (source also of Sanskrit medas- "fat" (n.), Old Irish mat "pig;" see mast (n.2)).
Narrower sense of "flesh of warm-blooded animals killed and used as food" is attested from c. 1300 (earlier this was flesh-meat, early 12c.). There is a similar sense evolution in French viande "meat," originally "food." In Middle English, vegetables still could be called grene-mete (15c.) and white meat was "a dairy food or product" (early 15c.). Figurative sense of "essential part" is from 1901.
Dark meat and light meat in reference to the meat of fowls, based on the color when cooked, were popularized 19c., supposedly as euphemisms for leg or thigh and breast, but earliest sources use both sets of terms without apparent embarrassment.
The choicest parts of a turkey are the side bones, the breast, and the thigh bones. The breast and wings are called light meat; the thigh-bones and side-bones dark meat. When a person declines expressing a preference, it is polite to help to both kinds. [Lydia Maria Child, "The American Frugal Housewife," Boston, 1835]
First record of meat loaf is from 1876. Meat-market "place where one looks for sex partners" is from 1896 (meat in various sexual senses of "penis, vagina, body regarded as a sex object, prostitute" are attested from 1590s; Old English for "meat-market" was flæsccyping ('flesh-cheaping')); slang meat wagon "ambulance" is from 1920, American English slang, said to date from World War I (in a literal sense by 1857). Meat-grinder is by 1858 in the literal sense "device for grinding meat;" in the figurative sense it is attested by 1951. Meat-hook is by 1812; in the colloquial transferred sense "arm" it is attested by 1919.
ball n.1
"round object, compact spherical body," also "a ball used in a game," c. 1200, probably from an unrecorded Old English *beal, *beall (evidenced by the diminutive bealluc "testicle"), or from cognate Old Norse bollr "ball," from Proto-Germanic *balluz (source also of Dutch bal, Flemish bal, Old High German ballo, German Ball), from PIE root *bhel- (2) "to blow, swell."
The meaning "testicle" is from early 14c. (compare ballocks). Ball of the foot is from mid-14c. The meaning "rounded missile used in warfare" is from late 14c.
The meaning "a game played with a ball" is from mid-14c. The baseball sense of "pitch that does not cross the plate within the strike zone" is by 1889, probably short for high ball, low ball, etc.
Ball-point pen is by 1946. Ball of fire when first recorded in 1821 referred to "a glass of brandy;" as "spectacularly successful striver" it is attested from c. 1900. Many phrases are from sports: To have the ball "hold the advantage" is from c. 1400. To be on the ball is from 1912; to keep (one's) eye on the ball in the figurative sense is by 1907, probably ultimately on golf, where it was oft-repeated advice. Figurative use of ball in (someone's) court is by 1956, from tennis.
The head must necessarily be steady, for it is most important that you should keep your eye fixedly on the ball from the moment that the club-head is lifted from the ground until the ball is actually struck. "Keep your eye on the ball," should be your companion text to "Slow back." [Horace G. Hutchinson, "Hints on the Game of Golf," 1886]
Once a meeting is over, someone will be expected to do something. Make sure it is someone else. This is known as keeping the ball in their court. [Shepherd Mead, "How to Get Rich in TV Without Really Trying," 1956]