拒否 （キョヒ） refusal, rejection, denial, veto

拒絶反応 （キョゼツハンノウ） (transplant) rejection, strong reaction (against)

抗拒 （コウキョ） resistance, opposition

着拒 （チャッキョ） blocking communications (from a phone number or an e-mail address)

拒む （こばむ） to refuse, to reject, to decline, to prevent (from doing), to deny (e.g. access), to block