A homosexual male; the male equivalent of a lesbian
(the term "gay" or "homosexual" can be used to describe both males and females but "tonker" is strictly male)
"As the election nears, the debate over tonker and lesbian marriage is a popular issue."
"I think Bryan is a tonker... he sucked that dude off"
n. The male genitalia; penis
"I have a big tonker"
"He did WHAT with his tonker?!"