An intransitive verb meaning to depart, leave, or set off (on a journey); nearly synonymous with 'to depart' and often used in writing or slightly literary contexts.
列車は予定時刻に発った。
The train departed at the scheduled time.
彼は朝早く家を発って新幹線に乗った。
He left home early in the morning and took the Shinkansen.
旅に発つ前に家族と写真を撮った。
Before setting off on the trip, I took a photo with my family.