The old graph for 食 is generally understood as a lidded vessel filled with food; some early forms add small marks that may show what is inside. Its outline changed greatly as the script became more regular, but the original idea stayed close: food in a container, ready to be eaten. That gave 食 both of its basic meanings, “food” and “to eat”.
A piece of culture
One character, two everyday voices In Mandarin, 吃 is the usual everyday verb “to eat”, while 食 often appears in words such as 食物, “food”. In Cantonese, 食 is itself the ordinary spoken verb: 食飯 (sik6 faan6) means “eat a meal”. It is a neat example of how the same written character can feel formal in one Chinese language and completely everyday in another.
Use it in a real word
食物
shíwù · sik6 mat6
food; foodstuff — the broad everyday noun in written Chinese