Possess is the opposite of Lack. Lack is related to Have. Have is related to Afford. 
Paint is related to Treatment. Treatment is a synonym of Intervention. Intervention is a type of Engagement. Engagement is related to Proposal. 
Possess <--Antonym--> Lack <--RelatedTo--> Have <--RelatedTo--> Afford 
Paint <--RelatedTo--> Treatment <--Synonym--> Intervention --IsA--> Engagement <--RelatedTo--> Proposal 