A derogitory term used to describe illegal immigrants from Mexico. This originates from them jumping the boat and swimming to shore (undetected) hence having 'wet backs'.
"Those lousy wet backs never do any work"
"Damn Robin's a filthy wet back!
....yeah so's Dolly man"
"That guy's a bit too wet back for my liking"
Taking a shower especially for the purpose of cleaning yourself, because you have run out of toilet paper.
The COVID-19 hoarders bought all the tp at Woolies so, if you'll excuse me, I'm shlowering.