Plain English Meaning
A way of measuring how fast a radio signal vibrates. One kHz means the signal cycles one thousand times every second. Pilots see kHz on the dials of older or low-frequency navigation radios.
Full Definition
A unit of frequency equal to one thousand cycles per second (1,000 Hz). In aviation, kHz is used to express the tuning frequency of low and medium frequency radio equipment, most commonly NDBs (non-directional beacons) and ADF receivers, which operate in the 190–535 kHz range.
Context Anchor
Seen in navigation and communication equipment discussions when radio frequencies are listed or tuned.
Derivation
From 'kilo-' (Greek 'chilioi', meaning thousand) and 'hertz' (named after German physicist Heinrich Hertz, who proved radio waves exist). So kilohertz literally means 'one thousand cycles per second.' Knowing this helps pilots see kHz and as the same kind of measurement at different scales — kHz is thousands, MHz is millions.