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.
- present perfect
- present tense
- preservability
- preservable
- preservation
- preservationism
- preservationist
- preservative
- preserve
- preserver
- preset
- presettable
- preshrunk
- pre-shrunk
- preside
- presidency
- president
- president-elect
- presidential
- presidentially
- president pro tem
- president pro tempore
- President's Day
- Presidents' Day
- Presidents Day