jamb

¹ American  

[jam] / dʒæm /

Or jambe

noun

1. Architecture, Building Trades.

   1. either of the vertical sides of a doorway, arch, window, or other opening.

   2. either of two stones, timbers, etc., forming the sidepieces for the frame of an opening.

2. Armor. greave.

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jamb ² American  

[jam] / dʒæm /

verb (used with or without object)

Obsolete.

1. an obsolete variant of jam.

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jamb British  

/ dʒæm /

noun

1. a vertical side member of a doorframe, window frame, or lining

2. a vertical inside face of an opening in a wall

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Etymology

Origin of jamb

1350–1400; Middle English jambe < Middle French: leg, jamb < Late Latin gamba, variant of camba pastern, leg < Greek kampḗ bend of a limb

Explanation

A jamb is one of the upright boards or posts that support a door or window frame. Your front door shuts securely in between two jambs. When a house builder frames a doorway, she sets two jambs at the sides of the opening, with what's called a lintel at the top. The door fits between the jambs. Windows have jambs too — if you replace your existing windows, you may need a whole new frame, including new jambs. The Old French origin is jambe, which means "pier or side post," but was originally "a leg or a shank," from the Late Latin gamba, "leg."

Example Sentences

The Green Party candidate running for a Senate seat in North Carolina stuck his arm between a door and its jamb.

From Salon • Mar. 5, 2026

The 10-year-old stood outside the only home he’d ever known — a home he could traverse in total darkness, whose every floorboard and door jamb he knew like the back of his hand.

From Los Angeles Times • Jan. 28, 2025

Thankfully none of players entering the locker room afterward clanked off the door jamb.

From Seattle Times • May 27, 2022

Doors are similar and need to close tightly against the jamb and sill weather stripping.

From Washington Post • Feb. 16, 2022

The window slid in a crooked path up its jamb.

From "Song of Solomon" by Toni Morrison