phi·lat·e·ly 
(fĭ-lătl-ē)
(fĭ-lătl-ē)n.
The collection and study of postage stamps, postmarks, and related materials; stamp collecting.
[French philatélie : Greek phil-, philo-, philo- + Greek ateleia, exemption from payment (because a postage stamp indicates prepayment of postage) (a-, without; see A-1 + telos, tax, charge; see telə- in the Appendix of Indo-European roots).]
phil′a·telic (fĭl′ə-tĕlĭk), phil′a·teli·cal (-ĭ-kəl) adj.
phil′a·teli·cal·ly adv.
phi·late·list n.