Definition
JAMMING
Denotes emissions that do not mimic Global Navigation Satellite System (GNSS) signals (e.g., GPS and WAAS), but rather interfere with the civil receiver's ability to acquire and track GNSS signals. Jamming can result in denial of GNSS navigation, positioning, timing and aircraft dependent functions.
Source: FAA Pilot/Controller Glossary (verbatim from the Federal Aviation Regulations).