I'm just a beginner armed with jisho dot org, but it does seem like they're entirely different words?
https://jisho.org/word/%E6%98%8E%E3%82%8B%E3%81%84 / https://jisho.org/word/%E6%98%8E%E3%81%8B%E3%82%8A (adjective vs noun but clearly just the same word in different form)
vs
https://jisho.org/word/%E8%BB%BD%E3%81%84 (light weight)
That was my thought path as well. The closest to a noun that came to mind would be karusa. I’m far from an expert in the language, so I’d be happy to be proven wrong.
Okay, if three of us agree, it is definitely wrong.