opset 

1) Quite a happy feeling

2)misspelling of ‘upset’

I’m so opset!
You make me opset.

opset by magicalmonkeys January 1, 2018

Opethian 

ADJECTIVE
Of or relating to the metal band Opeth. Usually describing something very gloomy, creepy, and haunting. often in black and white.

This photography sure is Opethian!

Opethian by Sam Owen February 23, 2009

opsec

Short for operational security.

In the current year, opsec is being used by an increasing number of everyday people to mask or spoof their online identities which are being aggressively tracked and recorded by governments and big tech.

Storing passwords in plaintext is terrible opsec.

opsec by 4qZYMd January 26, 2022

Opeth 

Progressive Death metal band formed in 1990; known for their blend of folk, metal, and progressive 70's rock, and Mikael Åkerfeld's brutal death growls and beautiful clean vocals. One of the most talented extreme metal bands around today.

Opeth is a very good band.

Opeth by ratsinthewall March 1, 2003

Opeth 

What you get when you take folk, prog, and death metal and mix in a blender of musical talent. When you listen to this music, the chills that go up your spine are astounding. Imagine standing on a windswept moor in the middle of nowhere, walking anyplace. The kind of desolate longing and anticipated dread that this style of scene conjures up is the essence of Opeth.

Face of Melinda
Death Whispered a Lullaby
Ending Credits
For Absent Friends
Moonlapse Vertigo
Blackwater Park

Opeth by King Leif January 10, 2005

Sudden Onset Autism 

Sudden Onset Autism, or S.O.A for short, is an extremely rare condition of unknown origin. Development of this disease is both abrupt and severe. As of now, the pathogenesis and mode of infection have eluded even the most qualified of research teams at Harvard, Hopkins, and Yale. Some have suspected that transmission occurs through contact with an infected person, especially prandially. There is still hope for a cure, although we may be decades away.

Infected Person: Hey man, let's go grab some lunch
Healthy Individual: what?! It's 3 in the morning. What's wrong with you
Infected Person: Well... it's lunchtime somewhere!
Healthy Individual: Oh God, you have Sudden Onset Autism... Please go away from me!

Sudden Onset Autism by burner90 May 14, 2018

opsat 

Communication device used by Sam Fisher of the Splinter Cell book/video games that resembles a PDA and is used to communicate to the support team in the NSA via wireless network

Sam details on your opsat

opsat by Sam Fisher L337 September 7, 2007