A suffix indicating that the substance, in the name of which it appears, is a ketone; as, acetone.

The suffix -one is used in organic chemistry to form names of organic compounds containing the -C(=O)- group: see ketone. Sometimes a number between hyphens is inserted before it to state which atom the =O atom is attached to. This suffix was extracted from the word acetone.

A termination indicating that the hydrocarbon to the name of which it is affixed belongs to the fourth series of hydrocarbons, or the third series of unsaturated hydrocarbons; as, nonone.