hex·ad 
(hĕksăd′)
(hĕksăd′)n.
A group or series of six.
[Late Latin hexas, hexad-, the number six, from Greek, from hex, six; see s(w)eks in the Appendix of Indo-European roots.]
hex·adic (hĕk-sădĭk) adj.
- extract
- extractable
- extractible
- extraction
- extractive
- extractively
- extractor
- extracurricular
- extraditable
- extradite
- extradition
- extrados
- extraembryonic
- extragalactic
- extrahepatic
- extra-high voltage
- extrajudicial
- extrajudicially
- extralegal
- extralegally
- extramarital
- extramundane
- extramural
- extraneous
- extraneously