What is Yolker?
1.
One who masturbates constantly.
used as an insult
"Hey you going to pro with Jeff?"
"No he's such a yolker..."
See
2.
The yellowish slime left in the crotch of a girl's panties usually due to over-horniess or a genital disorder.
Sarah always had a bright yellow yolker waiting for me in her underpants
See