This rare kanji has no clear standalone meaning. Treat its meaning as uncertain.
啛 combines 口 (mouth) with 妻, but the historical development and original meaning are uncertain.
A mouth 口 beside 妻 might suggest a wife speaking, but no clear meaning is attached to this shape.
For サイ, imagine a sigh (サイ) escaping from the mouth 口 of the wife 妻, even though the meaning is uncertain.