crenel

noun

1

a notch or open space between two merlons in a crenelated battlement

Synonym: crenelle

2

one of a series of rounded projections (or the notches between them) formed by curves along an edge (as the edge of a leaf or piece of cloth or the margin of a shell or a shriveled red blood cell observed in a hypertonic solution etc.)

Synonym: scallop crenation crenature crenelle

verb

1

supply with battlements

Synonym: crenelate crenellate