The building blocks of English

Affixes

nor-

An organic compound that is the parent of another.

The first element of normal.

This denotes the normal or parent form of the organic compound named in the stem, one which lacks one or more methyl groups. Examples are noradrenaline (in the US norepinephrine), a hormone that functions as a neurotransmitter; nortriptyline, a tricyclic antidepressant drug; and norgestrel, a synthetic progestin.