- (informal, usually uncountable) A thick, slimy substance; goo.
- 2014 December 23, Olivia Judson, “The hemiparasite season [print version: Under the hemiparasite, International New York Times, 24–25 December 2014, p. 7]”, in The New York Times:
- […] The flesh [of the mistletoe berry] is sticky, and forms strings and ribbons between my thumb and forefinger. For the mistletoe, this viscous goop – and by the way, viscous comes to English from viscum – is crucial. The stickiness means that, after eating the berries, birds often regurgitate the seeds and then wipe their bills on twigs – leading to the seeds' getting glued to the tree, where they can germinate and begin the cycle anew.
- (countable, informal, derogatory, dated) A silly, stupid, or boorish person.
- “goop” in Dictionary.com Unabridged, Dictionary.com, LLC, 1995–present.
- Oxford English Dictionary, 2nd ed., 1989.
- Random House Webster's Unabridged Electronic Dictionary, 1987–1996.