rectilinear

Pertaining to the measurement of one's asshole.

After a vigorous session of anal sex, Bob's anus had expanded to 3 rectilinear inches.

by C.S. Lewis Jr. September 4, 2004

Rectilinear distance

The gayest distance between any two points on a grid.

Josh: Hey what's the rectilinear distance from here to Taco Bell?
Andy: Shut up, fag.

by superjoe30 September 26, 2009

Rectilinear Motion

The formal mathematical term for anal sex.

John gave his student a hard rectilinear motion assessment.

by bakeshop February 17, 2010