trac·ery 
/ˈtreɪsəri/ noun
/ˈtreɪsəri/ noun [noncount] 1 : decorative patterns made in stone in some church windows
▪ This window is an example of Gothic tracery. 2 : lines that cross each other in a complicated and attractive pattern
▪ the delicate tracery of a butterfly's wing
▪ This window is an example of Gothic tracery.
▪ the delicate tracery of a butterfly's wing
