Plain English Meaning
A chart that tells pilots and controllers exactly how to say each letter and number on the radio, so 'B' and 'D' don't get confused and '5' and '9' don't sound alike.
Full Definition
A standardized list that assigns a distinct spoken word to each letter of the alphabet (Alpha, Bravo, Charlie, Delta, and so on) and a clear pronunciation to each numeral, used in aviation radio communication to prevent letters and numbers from being misheard.
Context Anchor
Seen in communication procedures when learning how to spell call signs, airport letter codes, or instructions over the radio.
Derivation
Phonetic' comes from the Greek phone, meaning 'sound' or 'voice.' A phonetic guide is therefore a sound-based guide — it tells you how something is spoken, not how it is spelled.