The Propyl reference article from the English Wikipedia on 24-Apr-2004
(provided by Fixed Reference: snapshots of Wikipedia from wikipedia.org)

Propyl

Have you considered sponsoring a child
In organic chemistry, propyl is a three-carbon alkyl substituent with chemical formula -C3H7. It is the substituent form of the alkane propane.

For example:

Image:propylethanoate.gif

This is "propyl ethanoate," an ester. The propyl group is attached to the molecule after the middle oxygen.