My very first thought was Bellend. Probably says more about me than you though.
Definitely would not use if the surname was N or D (Belle N/Belle D). Too close.
I’d be ruling it out of any name or potential to become Belle Church, Belle Ringer, Belle Ball, Belle -bottom, Belle Pepper, Belle Bell, Belle Campbell, Belle Bellamy, Belle Belmont, and so on.
Perhaps, as a PP, a longer name to fall back on?