1.When I check the definition of 'nerd' in the dictionary, I find the definition:
someone who is not fashionable and does not know how to act in social situations and who studies hard in school and is often interested in one subject.
So, when you use it in 'word-nerd'', do you mean the same meaning humorously, or there are  other connotations to(?) the word?
2. (For fun) Don't you think that 'behind one's back' is in front of them and therefore in their presence?!!!(I like, however, such phrases in languages.)
Thnx,
Rafee
There are multiple meanings, for example definition 2 here: Learner's Dictionary
"a person who is very interested in technical subjects, computers, etc."
See also: Â greatwhitesnark.com/2010/03/25/difference-between-nerd-dork-and-geek-explained-in-a-venn-diagram/
but put the usual "www" in front of that link. For some reason long links are getting truncated in this forum.
Testing at Grant's request ...
Done.
Back to Rafee's question: I'm going to disagree with dilettante and say that the meaning you cited, Rafee, is the only one I can think of. Â Dilettante's meaning is not a different one, it just uses different words. Â A nerd is one who is intellectually bright but lacking in social skills; whether the nerd's intellectual accomplishments are in computers, words, mechanical engineering, chess, particle physics or what-have-you doesn't change the basic idea.
And yes, it can often be used humorously or self-deprecatingly.