Plain English Meaning
A ground station that lets your aircraft measure how far it is from that station. The aircraft sends a signal, the station replies, and the equipment in the cockpit shows the distance.
Full Definition
A ground-based navigation aid that transmits a DME signal, allowing properly equipped aircraft to determine their slant-range distance from the station. A DME NAVAID may stand alone or be co-located with a VOR, ILS, or other navigation facility, and it is identified by name, frequency pairing, and station identifier on charts and approach plates.
Context Anchor
Seen on instrument procedure charts and in procedure-leg descriptions when a or is based on distance from a DME-equipped navigation facility.