English
incidency
From incident + -ency.
A compound of incident + -ency
Proto-Indo-European *ḱad- ‘to fall’
…
Latin cadō ‘to fall’
Latin incidō ‘to happen’
Latin incidēns ‘happening’
Middle French incident
English incident
Today it means
noun An incident; something incidental or circumstantial.
Language periods are conventional ranges, not dates for this word.
Etymograph / incidency