A part that is joined to something larger.
Something attached to another thing as an extra or subsidiary part; hanger-on.

ETYM Latin extensio: cf. French extension. Related to Extend.
1. A mutually agreed delay in the date set for the completion of a job or payment of a debt.
2. Act of expanding in scope; making more widely available.
3. Act of stretching or straightening out a flexed limb.
4. Amount or degree or range to which something extends; SYN. lengthiness, prolongation.
5. An additional telephone set that is connected to the same telephone line.
6. An educational opportunity provided by colleges and universities to people who not enrolled as regular students; SYN. extension service, university extension. + prikaži više

ETYM French prolongation.
The act of prolonging something; SYN. protraction, perpetuation, lengthening.