We found 2 dictionaries that define the word fall off the radar:

General (2 matching dictionaries)

1. fall off the radar: Merriam-Webster
2. fall off the radar: Wiktionary

Definitions from Wiktionary (fall off the radar) ▸ verb:  Synonym of drop off the radar ▸ Words similar to fall off the radar ▸ Usage examples for fall off the radar ▸ Idioms related to fall off the radar ▸ Wikipedia articles (New!) ▸ Words that often appear near fall off the radar ▸ Rhymes of fall off the radar ▸ Invented words related to fall off the radar