Stack Exchange wants to be a place where you can find answers to everything imaginable. So instead of closing questions as "just google it!", we are encouraged to answer them here itself.
Similarly, ELU aims to have answers to all possible questions about the English language and usage (within the scope defined in its help center).
But here's the thing, we don't aim to ourselves become an English dictionary, thesaurus, or a forum for analysis and criticism of literature.
So, questions on ELU asking for "what does this word mean?" should preferably also briefly include the context, what dictionary was referred to, what definitions were found, and why that research didn't help.
We don't mean to close everything by saying "just google it!". We ask only this, "please include the research you have done" and then we'll guide you from there.
Regarding that particular question about gentleman jockey, a quick googling gave me an idea of the meaning, even though I have never heard that in my 25 years on Earth, and even though I'm not a native English speaker. The OP has experience with the SE network, so I'm sure they know how to google things, and should have included in the question body why that did not help.