Amine classifications

Amines are organic compounds that are related to ammonia (NH3) where one or more of the hydrogens is replaced by a hydrocarbon group as shown for the three compounds below.

The terms primary, secondary and tertiary are commonly used in organic chemistry to describe the number of bonds to carbon at a particular atom.

For amines, the terms primary, secondary and tertiary refers to the number of bonds to carbon at nitrogen.  The amine is classed as

primary (1°) 
if the nitrogen is bonded to one carbon and two hydrogens
secondary (2°) 
if the nitrogen is bonded to two carbons and one hydrogen 
tertiary (3°) 
if the nitrogen is bonded to three carbons
 
primary secondary tertiary