カイ, エ, あ.う, あ.わせる, あつ.まる, あい, い
meeting, meet, party, association, interview, join
JLPT4 G2 S6 F4
The relevant seal inscription form is a variant form of 介# (reduce) + 曾 (pile → mass) → mass gathering that reduces/eliminates space → *meet*; *assemble* → (conduct an) *interview*.
[Full Kanji Etymology List]