Definition of illegal sometimes disparaging + offensive : a person who enters or lives in a country without the documentation required for legal entry or residence
aerial noun [C]. âº a âstructure made of âmetal ârods or âwires that âreceives or âsends out âradio or âtelevision âsignals.
Altitude means height above the ground or above the sea level. Common uses include aviation (flying, parachuting, gliding), and geography / surveying. In geometry it is also used as the height of the object itself. Generally, altitude is the distance one thing is above another thing. This is in the vertical or up direction. For the height of the ground (such as for hills and mountains), the word elevation is also used and might be a better choice.