Definition
To masturbate by stimulating one's vagina.
How People Actually Use It
(adverb) a phrase you say to someone when you see them scratching their butt crack or anywhere in the vicinity of the butt crack. Can also be used when you see them pulling out their underwear or pants from the butt crack area; can also be used when a female does this in the lower frontal extremity
"Itch in the Ditch"
Source: Urban Dictionary