Need is the opposite of Sufficient. Sufficient is the opposite of Bare. Bare is a synonym of Mere. 
Adult is the opposite of Man. Man is related to Girl. Girl is related to Ribbon. 
Need <--Antonym--> Sufficient <--Antonym--> Bare <--Synonym--> Mere 
Adult <--Antonym--> Man <--RelatedTo--> Girl <--RelatedTo--> Ribbon 