Illustrated Glossary of Organic Chemistry

Septet: In NMR spectroscopy, a split signal composed of seven lines, close together. The height of the lines will be close to 1:6:15:20:15:6:1 ratio.

Idealized septet
Lines in a 1:6:15:20:15:6:1 ratio 		  
"Leaning" septet


The simulated 1H-NMR spectrum of 2-chloropropane has a septet at 3.68 ppm due to the methine proton. Click on the image for a larger version.