Nowadays it can be good or bad.
In the past it was inherently bad, but it has undergone the phenomenon of reappropriation , which causes insults to become a "badge of honour" for the insulted group.
In my personal experience, nerd was an insult most (~ 90%) of the time until the mid-late 2000s, when the concept of a "nerd culture" became surprisingly popular.
Of course, nerd as " person who follows nerd culture " and nerd as " person who studies too much " do not always overlap.
ell.stackexchange.com/users/42528/J. Siebeneichler
If they are referring to an "intelligent" person like you say then they most probably mean: a person who is extremely interested in one subject, especially computers, and knows a lot of facts about it — Cambridge Dictionary Example, I'm a real grammar nerd.
So, no it is not in the bad or negative sense
but you still have to be careful with this word some people might find a bit offensive to be called a "nerd" especially when this word has a first definition that is kind of negative.
ell.stackexchange.com/users/43818/Arrowfar
I don't agree nerd is restricted to intelligent.
A nerd can use the n word to describe themselves but other people should not.
A nerd can say he is a nerd pack like me.
As a non nerd there are so many ways to express without using the n word.
He/
she is into computing.
He is a car racing enthusiast.
All she can talk about is medicine.
He is cryptography nerd from MIT that works for the NSA
is OK.
It clearly does not have the strict negative connotation of the other n word.
Just making a silly comparison.
ell.stackexchange.com/users/42757/paparazzo
In some language communities, "nerd" is a loaded word; for example, when used to describe a boy or man, nerd can carry connotations of being easy to push around and/or sexually frustrated.
In some language communities, it's basically considered inoffensive; but unless you want to risk offending the other person, I don't think this a good term.
And I think that, when speaking to men especially, it's safer to assume that the other person considers themselves "dominant" (not like a bully; more like, someone you don't f**k with), so best to choose language that doesn't convey a disconnect between how you're viewing the other person and how they view themselves.
This applies w/o much qualification when talking to women, too; if you're talking to a woman, for example, keep in mind that she may well be elected in as a parliamentary MP one day, or become the CEO of a major corporation, or end up owning a large and highly successful business, etc.
Such a woman may not appreciate being called a "nerd", I think.
ell.stackexchange.com/users/43857/goblin
A nerd is someone with a drive to study.
The driver can exist for any of a bunch of different reasons.
There are also different areas of focus.
Eventually, though, a nerd, in order to be a nerd, must have a certain "love of the subject".
And then there are shy nerds, who will cringe upon hearing the word, and less shy nerds, who will openly affirm, part of their identity, as a nerd.
For a reference and idea, please see the movie T.G.I.F by Katy Perry , which might be able to give you some ideas about why one would be, or want to be, or end up being, a nerd.
ell.stackexchange.com/users/33778/Jack Maddington
My friends always use "nerd" to describe an intelligent person, but when I searched its meaning online, I found that it's not really a good word.  "A foolish or contemptible person who lacks social skills or is boringly studious."  Oxford Dictionaries  I've become so confused with this word. Is it an insult or a compliment?
Is it good to call someone "Nerd"?
ell.stackexchange.com
<word-usage><word-meaning>
ell.stackexchange.com/questions/107687
ell.stackexchange.com/users/38653/Řazan Ďawud
Nowadays it can be good or bad. A nerd must have a certain love of a subject. However, nerd  was an insult most of the time until the mid-late 2000s, when the concept of a "nerd culture" became surprisingly popular. The insult of "nerd" has undergone the phenomenon of  reappropriation , which causes insults to become a "badge of honour" for the insulted group. The term is ambiguous. In the past it was inherently bad, and could even mean "an easy to push around/sexually frustrated man". However, it has been reappropriated, so now it has become somewhat more popular. Now, a nerd is a studious person with love for a certain subject.
The term is ambiguous. In the past it was inherently bad, and could even mean "an easy to push around/sexually frustrated man". However, it has been reappropriated, so now it has become somewhat more popular. A nerd is a studious person with love for a certain subject.