Noun, pl. notches
1. A family of receptors, which upon binding with ligands, plays a major role in neurogenesis, specifically during lateral inhibition (wherein neuroblasts are singled-out from the neuroectoderm) and during binary cell fate specification (wherein ectodermal cells are prevented from differentiating into neuroblasts). (biology-online.org)
1. A deep close pass; a gap. (merriam-webster.com)
2. A rounded indentation cut into the pages of a book on the edge opposite the spine. (merriam-webster.com)
3. The location in a range of mountains of a geological formation that is lower than the surrounding peaks. (wordnetweb.princeton.edu)
Word origin: From Middle French oche “notch,” from Old French ochier “to notch,” of unknown origin. Said to be unconnected to nock.
1. Cut or make a notch into. (wordnetweb.princeton.edu)
2. Notch a surface to record something. (wordnetweb.princeton.edu)