This rare kanji has no clear standalone meaning. Treat its meaning as uncertain.
礌 combines 石 (stone) with 雷 (thunder). The exact historical development is uncertain, but it likely relates to stones or thunder in some way.
A stone 石 beside thunder 雷 suggests something heavy and loud, like a thunderous rockfall, but its actual meaning is unclear.
For ライ, imagine a stone struck by lightning with a loud 'rye' sound: rye -> ライ, like thunder hitting rock.