sub·har·mon·ic 
(sŭb′här-mŏnĭk)
(sŭb′här-mŏnĭk)adj.
Of, relating to, or being a wave with a frequency that is a fraction of a fundamental frequency.
- extrasystolic
- extraterrestrial
- extraterritorial
- extraterritoriality
- extraterritorially
- extratropical
- extrauterine
- extravagance
- extravagancy
- extravagant
- extravagantly
- extravaganza
- extravagate
- extravasate
- extravasation
- extravascular
- extravehicular activity
- extraversion
- extraversion
- extravert
- extravert
- extraverted
- extraverted
- extra-virgin olive oil
- extremal