breathing through the nose, snorting, wife, one's old lady
嚊 centers on nasal actions and sounds: breathing through the nose or snorting. The colloquial meanings 'wife' or 'one's old lady' are likely unrelated slang usages that do not share a clear conceptual link with the nasal sense.
嚊 combines 口 (mouth) with 鼻 (nose), suggesting a compound related to nasal breathing or sounds made through the mouth and nose. The exact historical development is uncertain, and the colloquial 'wife' meaning likely arose through unrelated phonetic borrowing or slang.
A mouth 口 beside a nose 鼻: imagine someone breathing loudly through their nose while their mouth is slightly open, producing a snorting sound.
For ヒ, picture a person snorting so hard they make a high-pitched 'hee' sound: hee -> ヒ, and the snort comes right from the nose.