Noun
(engineering) Electromagnetic waves with frequencies around one terahertz.
(engineering) Especially electromagnetic waves in the range 0.1-30 THz (or subranges there of, see T-rays or T-waves).
submillimeter wave radiation
Source: en.wiktionary.orgTerahertz radiation main Terahertz radiation is a region of the spectrum between far infrared and microwaves. Source: Internet