Apology is related to Say. Say is related to Voice. Voice is related to Speak. 
Involve is a type of Refer. Refer is a type of Send. Send is a synonym of Broadcast. 
Apology <--RelatedTo--> Say <--RelatedTo--> Voice <--RelatedTo--> Speak 
Involve --IsA--> Refer --IsA--> Send <--Synonym--> Broadcast 