pink slime

Noun

Meaning

(paper manufacture) An undesirable pink-colored microbial mass occurring in the slurry used in making paper. [from 1951]

(informal, dysphemistic) A meat byproduct produced from scraps by heating and then treating with ammonia to produce a food additive. [from 2002]

Used other than figuratively or idiomatically: see pink,‎ slime. Slime which is pink.

Source: en.wiktionary.org

Pink slime was beef, not chicken. Source: Internet