A soft shoe or slipper, especially one for a baby or young child; also, a short woman's boot.
From 'boot' with the French diminutive suffix '-ee' (also seen in 'trustee'). The term emerged in the 19th century to describe small or soft versions of boots.
The '-ee' suffix in English (bootee, trustee, employee) comes from French legal and formal vocabulary. It's one of the reasons English has so many ways to modify words—we borrowed whole patterns from French!
Complete word intelligence in one call. Free tier — 50 lookups/day.