1. a sure thing; a lock; goal attainment is assured; prospects are brilliant

2. all over it; about to take care of with gusto

From the tendency of thongs and other tightfitting swimwear to become wedged where the sun never shines

"In there like swimwear" is "in like Flynn" for a new millenium. Can you name a single Errol Flynn movie? But everyone knows (and loves) the Thong Song.
"Make friends with her friends and you'll be in there like swimwear."
from The Player's Rulebook
by mandingoe June 15, 2004
When you're playing a movement character and go absolutely beserk by shoving your fire arm up the enemy team's anal cavity.
by hardstuckval December 20, 2020
person 1: i thinke we could do it

person 2: i know we in there like swimwear
by alex smalls September 24, 2006
A made up term, scrum eaters often use this saying to distract from the fact that they want to eat your scrum
In there like swimwear is not a real phrase, I just made it up because of the scrum.
by KreatureFeature September 14, 2022