give, provide
餽 centers on giving or providing something, often in a formal or ceremonial context. The meanings "give" and "provide" are straightforward applications of this idea.
餽 combines 飠 (food) with 鬼, which likely contributes the sound. The character is associated with giving or providing, possibly originally related to offering food.
The left side 飠 relates to food, and the right side 鬼 looks like a ghost. Imagine a ghost offering food to someone: it gives and provides.
For キ, picture a key being given to unlock a door: key -> キ, and the act of giving is the core meaning.