Engagement is a synonym of Involvement. Implication is a type of Involvement. Implication is a type of Accusation. Accusation is etymologically related to Accuse. 
Strange is the opposite of Normal. Normal is related to Usual. Usual is related to Description. Description is related to Past. 
Engagement <--Synonym--> Involvement <--IsA-- Implication --IsA--> Accusation --EtymologicallyRelatedTo--> Accuse 
Strange <--Antonym--> Normal <--RelatedTo--> Usual <--RelatedTo--> Description <--RelatedTo--> Past 