An astragal is a moulding profile composed of a half-round surface surrounded by two flat planes (fillets).[clarification needed] An astragal is sometimes referred to as a miniature torus. It can be an architectural element used at the top or base of a column, but is also employed as a framing device on furniture and woodwork.
The word "astragal" comes from the Greek for "ankle-joint", ἀστράγαλος, astrágalos.[1]