This rare kanji has no clear standalone meaning. Treat its meaning as uncertain.
齇 combines 鼻 (nose) with 虘, which likely contributes the sound. The exact historical development is uncertain.
With 鼻 (nose) on the left, 齇 likely relates to the nose, but its specific meaning is unclear. Imagine a mysterious nose condition represented by the complex right side.
For サ, picture a person sighing 'sah' while touching their nose: sah -> サ, and the nose component 鼻 ties it to the kanji.