to cheat
諆 centers on deception through words: to cheat or mislead someone by saying something false.
諆 combines 言 (speech) with 其, which likely contributes the sound. The structure suggests deception through words.
Words (言) that are not what they seem (其 as a container of hidden intent) come together: 諆 is speech used to cheat.
For キ, imagine a key (キー) that unlocks a false promise: the key sound cues キ, and the deceitful words lock the victim in.