Word: fastcore
Part of speech: Noun
Syllables: fast
core
Definition: Alternative form of thrashcore;  is a fast tempo subgenre of hardcore punk that emerged in the early 1980s
Morphemes:
Affix: fast
Language: en
PoS: Adjective
Meaning: Steadfast, with unwavering feeling. (Now mostly in set phrases like fast friend(s) .)
Affix: -core
Language: en
PoS: Suffix
Meaning: Applied to various (often specialised and underground) genres of music and subcultures.