thanks, reward
犒 centers on expressing gratitude or giving a reward, often in the context of thanking someone for their efforts or service.
犒 combines 牜 (cow) with 高, which likely contributes the sound. The exact historical development is uncertain, but the character is associated with rewarding or thanking, possibly originally involving cattle as a reward.
A cow (牜) is raised high (高) as a reward or token of thanks for hard work.
For コウ, imagine a cow being rewarded with a high-five: cow -> コウ, and the cow is thanked for its service.