Tight fitting clothing to keep your ass warm in cold conditions, or cold in warm conditions
Under Armour (UA) Cold Gear keeps you warm, UA Warm Gear keeps you cold, UA All Season keeps you cold and warm
by Skare October 21, 2005
Clothes that rednecks who think they're all star baseball players who get all the girls. Football players use to wear it underneath their jerseys and pads. Most baseball players who ride the bench wear it.
I wear Under Armour so I must be the best baseball player out there!

All the ladies love my Under Armour!
I wear Under Armour to distract everyone from noticing I don't get any play time!

Wannabe Baseball Douche JerkDick Cocksucker Loser Ladybeater benchwarmer
by GloseUpG October 13, 2015
Clothes that rednecks who think they're all star baseball players who get all the girls. Football players use to wear it underneath their jerseys and pads. Most baseball players who ride the bench wear it.
I wear Under Armour so I must be the best baseball player out there!

All the ladies love my Under Armour!
I wear Under Armour to distract everyone from noticing I don't get any play time!

Wannabe Baseball Douche JerkDick Cocksucker Loser Ladybeater benchwarmer
by GloseUpG October 13, 2015
clothes that athletes wear under their jerseys to "keep warm"...costs a shitload
this is soo cool...says the girl with under armour
by cooldude24 October 29, 2006
Lightweight performance apparel popularized in the breakdown by Big E and his iron pumping friends, including JT the rookie and Coach. They participate in a supervised after-hours tackling club in a warehouse, and do not appreciate Cheese stopping by in a Cotton XXL shirt. They started this thing and are just trying to prevent everyone from bringing them down.
The house is paramount
Will you protect this house?
I will I will
Under Armour!
Woo!
by Dan November 24, 2003
Under Armour sports apparel that is inappropriately worn during public, non-sporting events (eg: bars, parties, classroom, restaurants, etc) in an attempt to pass it off as fashionable.
Chris: "Look at that douche bag wearing Social Under Armour."

Pete: "No wonder he is alone."
by Lafferty Daniel August 7, 2008
An Under Armour Mom is a woman between the age of 25 and 50 (there have been sightings of UAM's up to 65 years old, however) who has children, is currently married or divorced, and thinks she is an athlete. She attends yoga class every now and then, she might even go for a quick jog with her baby in the stroller, or participate in a triathlon "for the challenge" (rides a mountain bike with aero bars, doesn't really know how to swim). Due to her active and healthy lifestyle which makes her better than everyone else, she requires that her clothing express her passion for moderate exercise to her peers. She will regularly spend hundreds of dollars on Under Armour clothing and wears it on a regular basis even when not "training". T-Shirts that say "ATHLETE" on them, or "TRAIN HARD" or "PROTECT THIS HOUSE" are slogans of choice. When it's cold outside, she needs some "Coldgear". When it's hot outside, she seems some "Heatgear". The performance enhancing microfibers help her perform better, whether it be kicking the soccer ball around with her family, or picking up a pizza in her gigantic SUV.

She is a poser.
Some guy: Wow look at all that Under Armour gear that lady just bought, she must be preparing for some serious athletic training in the near future.

Another guy: Yeah, she's so cool. I wish I was an athlete just like her.

Under Armour Mom: *puts on earbuds playing Journey's greatest hits and power walks in the mall*
by The Crab Rangoon September 14, 2011