From frei (“free”).

• IPA^(key): /ˈfʁaɪ̯o/

Freio n (strong, genitive Freios, plural Freios)

1. (childish, regional, playground games, western Germany) in a game such as tag, an area where a player cannot be caught

   Synonyms: (northern Germany) Klippo, (Austria) Leo

   Äh, das gilt nicht! Ich bin im Freio.

   (please add an English translation of this usage example)