to quarrel, to wrangle
誩 centers on verbal conflict: two sides speaking against each other, quarreling or wrangling with words.
誩 is formed by doubling the speech radical 言, visually representing two voices in opposition. The exact historical development is uncertain, but the structure clearly suggests argument or dispute.
Two 言 (speech) radicals side by side look like two people talking over each other, quarreling and wrangling with words.
For ケイ, imagine a heated quarrel where one person yells 'Kay!' as a sharp retort: Kay -> ケイ, and the two 言 sides keep arguing.