look up any word, like bukkake:
 
1.
a favor or help, something like that.
Hey can you do me a solid?
by S-Dot December 02, 2004
 
2.
Like a favor with your bros but it matters more
A Favor: "Can i borrow a nickle"

"Yea sure"

A Solid: "Yo check out that babe at the bar"

"I'll wing man that bro, dont worry, i got this"

A Favor: "I need a pen"

"Take this"

A Solid: "I shot that bitch at the bar"

"I'll help with the body"
by Chris Boshs Neck October 15, 2012
 
3.
when a penis is standing up ready for lovemaking
look at Jordan, he's sporting a solid coz he's looking at porn!
by Jordan's friend October 19, 2007