The word dick is generally considered offensive and is marked so in dictionaries. But there is also a meaning of detective that it carries. I usually find no derog indication for this meaning.
Is it offensive to call a detective friend of mine a dick?
EDIT (thanks to Kristina): I want to know if the usage of this word to refer to detectives is offensive in practice, though the dictionaries may opine otherwise. The question is general and not about how I could call my friend đŸ™‚
Best Answer
While current usage may mark dick as offensive ("a man who you think is unpleasant and stupid" per Macmillan), the same entry in Macmillan succinctly summarizes dick in the sense of "private detective" as "informal, old-fashioned."
In other words, you can use "dick" in this sense if you want to sound like a character from a Mickey Spillane novel, or a film noir movie.