Likely a shortened affectionate spelling of Leah/Lydia-style names, functioning as a concise modern nickname form.
Leddi is likely a shortened affectionate spelling of Leah or Lydia-style names, functioning as a concise modern nickname form. That kind of reduction often gives a name a more intimate and informal personality.
Leddi feels brisk, soft, and easy to wear. It has the character of a familiar nickname made into a stand-alone name, which suits modern taste for compact, friendly forms. Its rarity keeps it from feeling generic, while its sound keeps it approachable.