A girls dick is a name given to a person, usually male who is being cowardly, pussywhipped, or just extrememly ball-less in cases that require them.Derived from the word "girls blouse" however more of a derogative term. Usually used whilst in presence of mates/ bros to express dissapointment or to persuade.Pretty much saying that someone who is a girls dick is a pussy.
Paul:"Oi bro just finish that jar of moonshine"
Andrew:"Nah bro, i cant i got work in the morning"
Paul:" haha ur a fucking girls dick bro,just do it"
Andrew:(sarcasticaly)"yeh heaps bro"