Insiduous 

A leafless tree that looks threatening and possibly harmful. Typically in a dark forest.

"Holy shit! Those insiduous trees are grabbin' Snow White! Run, Bitch, Run!"

Insiduous by Trrumoi February 19, 2018

Insiduous 

Moist or slightly wet.

All this foreplay is making me Insiduous.

Insiduous by THEGREATESTMANONTHISPLANET June 2, 2011

insidious 

Insidious (adverb insidiously)

developing in a very gradual, in a stealthy manner, with the intend of causing damage.

Prostate Cancer is an insidious disease.

insidious by piece September 18, 2006

Insepuous 

A word used to describe someone who can only otherwise be described as a drizzling cloud resembling a cantering or prancing reindeer on a sad or rainy day.

Seb is insepuous today.
That rain cloud is insepuous.
His actions could be described as rather insepuous.

Insepuous by aw_wild August 3, 2019

Insidiosity

The action of having a large or long wood

His wood is large beyond comprehension, it’s insidiosity.

Insidiosity by Smoked Paprika August 16, 2021

insideoutable 

the ability for an article of clothing to be turned inside-out.

I decided not to buy the thick coat, because that shit wasn't insideoutable.

insideoutable by Steaz December 17, 2010

Insidious 

A scary film

Just watched Insidious it was shit scary

Insidious by xizzie3 October 27, 2011