Definition
Tel is the chemical symbol for tellurium, a brittle, silvery-white metalloid element (atomic number 52) used in small quantities in certain alloys to improve machinability and in some semiconductor and thermoelectric applications.
Plain English
Tel is the short symbol for tellurium, a rare metal-like element sometimes added to other metals to make them easier to work with.
Context Anchor
Seen in airport information listings, notices, and contact details where a pilot may need to call an office, airport, or control facility.
Derivation
From Latin tellus, meaning earth. The element was named because it was discovered in earth ores, paired conceptually with uranium (named after the planet Uranus) and selenium (named after the moon).
Why Pilots Care
The correct TEL concentration prevents detonation that can destroy an engine in flight.
Intuition Check
Do not treat Tel as an aircraft system or navigation code here. In this context, it simply marks a telephone contact.
Example Sentence 1
The alloy specification listed Tel as a minor constituent added to improve machining characteristics.
Example Sentence 2
Mechanics verify TEL content on the fuel receipt before adding avgas to the tanks.