par·a·syn·the·sis 
(păr′ə-sĭnthĭ-sĭs)
(păr′ə-sĭnthĭ-sĭs)n. pl. par·a·syn·the·ses (-sēz′)
The formation of words by a combination of compounding and adding an affix, as in downhearted, formed from down plus heart plus -ed, not down plus hearted.
par′a·syn·thetic (-thĕtĭk) adj.