参加
さんか · sanka · JLPT N3 · noun
engagement
🎟️ 参加 = take part (参) + add (加): add yourself to the group
参 means to join or take part, as in 参考 (reference) and 参る (to go, humble). 加 means to add, as in 追加 (addition). Participation is literally joining in and adding yourself. Used with する: 会議に参加する = to take part in a meeting.
加 — force 力 + mouth 口
加 is traditionally analyzed as a compound of 力 (strength) and 口 (mouth), suggesting boasting or exaggerating one's effort with words. From this it extended to the meaning 'to add' or 'increase'. Today it is used broadly for addition, both literal and figurative.