The act of having nothing to say in conversation, so you just sit there with your mouth closed, looking unattractivally thin-lipped.
by amireal August 26, 2010
Get the thin-lippedmug. When someone is giving a blowjob and they tuck their teeth behind their lips, making their face look like an old lady with no teeth, gummin' your dick around her mouth.
by Chingthething December 11, 2017
Get the The Old Lady Thin Lipmug.