Pretty Little Sluts. A play off the show "Pretty Little Liars". Moslty used for making fun of it for it's slutty characters.
Dan: Yeah, my sister wouldn't give me the remote so I had to watch that stupid show pretty little liars
Tom: Oh you mean pretty little sluts, PLS?
Dan: Exactly.
Puppy Love Syndrome: usually occurs in teenagers and it is when they think that they are in love, but in reality it is just puppy love.
Dad 1: Ya i had 2 take hi in to the doctor the other day...
Dad 2: y?
Dad 1: he has a bad case of PLS..
Dad 2: o....is that like mono?
Dad 1: nope its Puppy love syndrome....
Dad 2: o shit i hope my daughter does'nt get infected too....
or "lateral secure position." A technique used by emergency responders to orient an unconscious person so that they're slightly on their side in order to keep them from choking on their own vomit. Used often to describe being blackout drunk, whether or not you actually passed out or were put in actual PLS
Bro I went way too hard last night, ended up sloshed and in near PLS