From Bibliotheca Anonoma

Fa is the fourth syllable in Solresol's alphabet. It can be represented with the written or spoken 'fa', the letter 'f', the color green, a falling line (in the Solresol stenography), the number 4, the musical note F (in fixed do solfège), or the fourth note of any major musical scale (in movable do solfège). It is preceded by the note mi and followed by the note sol.

The word fa means "to."

Four-syllable words beginning with the syllable fa are generally related to "country, agriculture, war, the sea, and travel."

The word fafa, sometimes written as FA, indicates that a verb is in the conditional tense.

Words beginning with fa that are either four syllables with a repeated syllable in them or three syllables are generally dedicated to sickness and medicine. It shares this designation with sol.