デカチン

noun, noun which may take the genitive case particle 'no'

large penis; huge dick

Vulgar slang term used among close friends or in crude contexts. Not appropriate in polite conversation.

• あいつはデカチンらしいよ。

  I heard that guy has a huge dick.

• デカチン自じ慢まんをするな。

  Don't brag about your big dick.