Term for a word "nollie"
Solution 1:
The word seems to be "jargon"
MW:
jargon noun
1 : the technical terminology or characteristic idiom of a special activity or group
sports jargon
Or, in your case, skateboarding jargon.
From Wikipedia
Marnell executes a "switch frontside flip" at the Melbourne Museum location, described as "gnarly" (skateboarding jargon for something that is extraordinarily good ...)
More informally, skateboarding talk/speech/language.