error, mistake, deceive, mislead
詿 centers on communication that goes wrong: an error or mistake, especially one that deceives or misleads someone.
詿 combines 言 (speech) with 圭, which likely contributes the sound. The character expresses speech that is erroneous or deceptive.
Words (言) that are as unreliable as a cracked jade tablet (圭) lead to errors and deception.
For カイ, imagine a sly character named Kai who always speaks (言) with a misleading smile: Kai -> カイ, and his words are full of mistakes.