A lancet window is a tall, narrow window with a sharp lancet pointed arch at its top. It acquired the “lancet” name from its resemblance to a lance. Instances of this architectural element are typical of Gothic church edifices of the earliest period. Lancet windows may occur singly, or paired under a single moulding, or grouped in an odd number with the tallest window at the centre.
The term lancet window is properly applied to windows of austere form, without tracery. Paired windows were sometimes surmounted by a simple opening such as a quatrefoil cut in plate tracery. This form gave way to the more ornate, multi-light traceried window.