Indeed. Never gave a second thought to the word but apparently it's the name of a young male servant. The pronunciation ends with a nasal vowel as there is no trailing "e" at the end. In IPA that's /ɡaʁ.sɔ̃/. If you say /ɡaʁ.ɔn/ it makes it sound female.

Un patron = male owner

Une patronne = female owner