IPA: /ˈɛəˌwɜːrði/
KK: /ˈɛrˌwɜrði/
In good condition and safe to fly; suitable for use in the air.
The aircraft was inspected and deemed airworthy before the flight.
Comparative: more airworthy
Superlative: most airworthy
Airworthy → It is formed from "air" (meaning the invisible mixture of gases surrounding the Earth) and "worthy" (from Old English "weorþig", meaning having worth or value). The word "airworthy" means having the necessary qualities or conditions to be safe and suitable for flying in the air.
Think of something that is 'worthy' ('worthy') to fly in the 'air' — that's what makes it airworthy.