Ajoure is a style of jewellery design similar to filigree

Filigree

Filigree is a delicate kind of jewellery metalwork made with twisted threads usually of gold and silver or stitching of the same curving motifs. It often suggests lace, and in recent centuries remains popular in Indian and other Asian metalwork, and French from 1660 to the late 19th century...

, which leaves open spaces in the worked metal. Unlike filigree, the holes are usually cut from the metal rather than being incorporated during the process of construction. It is usually used in the making of gold jewellery, such as pendants and brooches. The result is reminiscent of the style of lace

Lace

Lace is an openwork fabric, patterned with open holes in the work, made by machine or by hand. The holes can be formed via removal of threads or cloth from a previously woven fabric, but more often open spaces are created as part of the lace fabric. Lace-making is an ancient craft. True lace was...

 known as "ajour"

Cutwork

Cutwork or cut work is a needlework technique in which portions of a textile are cut away and the resulting "hole" is reinforced and filled with embroidery or needle lace.Cutwork is a related to drawn thread work...

, hence the term.