The vertical piece that forms the side of a doorway or window opening.
From Old French 'jambe' meaning 'leg,' derived from Late Latin 'gamba' meaning 'leg' or 'hoof.' Door and window jambs are called 'legs' because they stand upright and support the horizontal lintel above, just like legs support a body. The architectural term preserves this body metaphor — buildings have 'legs' (jambs) that hold up their 'arms' (lintels). It's the same root that gave us 'jambon' (ham) in French, literally 'leg meat.'
Door frames have legs! The vertical sides of doorways are literally called 'legs' because medieval builders thought of architecture in terms of body parts — jambs are the legs that hold up the lintel (the arm stretched across the top). This same 'leg' word gave French its word for ham, so door jambs and ham sandwiches share the same root.
Complete word intelligence in one call. Free tier — 50 lookups/day.