Definition of hexad in English:

hexad

noun

technical
  • A group or set of six:

    ‘each segment, down to the tiniest hexad of cilia, is practically identical in shape’
    • ‘These axes are, respectively, diads, triads, tetrads, and hexads.’
    • ‘Unfortunately there are not hexads or octads in nature.’
    • ‘The duodecad can be considered as two hexads, upper and lower; as three tetrads, working in dynamic cooperation; or as four triads in a synthesis of immanence and transcendence.’
    • ‘Two lyre-like instruments, Kitharas I & II, date from 1938 and have twelve hexads per instrument.’

Origin

Mid 17th century (denoting a series of six numbers): from Greek hexas, hexad-, from hex six.

Pronunciation:

hexad

/ˈhɛksad/