ほぞ
ほぞ 【木材の 】〘fix 〙 a tenon 〘into a mortise 〙.▸ 柱にほぞ穴をあける cut a mortise in [mortise ] 〘a pillar 〙.
ほぞ 【臍 】【へそ 】the navel .ほぞを固める make up one's mind / resolve / determine .ほぞをかむ deeply regret / feel very sorry .