rectumlinear 

contained by, consisting of, or moving in a rectal line or rectal lines.

relating to a rectal line or lines.

i've been backed up for days, my digestive track has gotten real rectumlinear.

that's some dirty fucking underwear, skidmarks are rectumlinear

neither my health professor, nor my geometry professor could tell me the definition of rectumlinear.

rectumlinear by Therealbluntmaster June 7, 2017

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.

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

rectalinear 

(Noun): Defined by, consisting of, or moving in a manner of an asshole.

I don't know what his problem is but that was totally rectalinear of him.

rectalinear by Frenetic1 March 11, 2018

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.

Rectilinear distance by superjoe30 September 25, 2009

Rectilinear Motion 

The formal mathematical term for anal sex.

John gave his student a hard rectilinear motion assessment.

Rectilinear Motion by bakeshop February 16, 2010