1
to clash;to collide;to conflict;to coincide
試験の日が私の姉の結婚式とかち合った。
The date of the examination clashed with my sister's wedding.
2
to meet (by chance);to come across;to run into
Other forms
搗ち合う 【かちあう】 (rarely used kanji form) · 搗合う 【かちあう】 (search-only kanji form)