hold in mouth or between teeth
啣 centers on holding something in the mouth or between the teeth, like a dog carrying a bone or a horse accepting a bit.
啣 combines 口 (mouth) with 卸, which likely contributes the sound カン and relates to the idea of holding or carrying. The exact historical development is uncertain.
The mouth radical 口 beside 卸 suggests a mouth holding onto something. Picture a horse with a bit in its mouth, firmly held between its teeth.
For カン, imagine a can held in a dog's mouth: can -> カン, and the dog carries it proudly.