Due to being possessed by Falcon Knights, Lancefaire is a female only skill, barring inheritance. This is similar to Axefaire which is wielded by the male-only class Berserker.
Lancefaire is the only physical weapon skill given to a class that can wield two weapons. It is likely Falcon Knights received this skill due to Awakening lacking a class that wields lances exclusively.
This makes the Falcon Knight class analogous to the Sage class in the manner that they both wield a single weapon type and staves.