1. fi - Noun
2. fi - Preposition
3. Fi - Proper noun
fi
(music) The solfeggio syllable used to indicate the sharp of the fourth note of a major scale.
(in combination) Abbreviation of fidelity. (e.g. in hi-fi, lo-fi, or wi-fi)
(in combination) Abbreviation of fiction. (e.g. in sci-fi)
fi
(Jamaica) Alternative form of to
Fi
Short form of the female given name Fiona.
Abbreviation of factor I. (clotting factor I)
(law enforcement) Initialism of field interview/interrogation.
(automotive) Initialism of fuel injection.
Source: en.wiktionary.org