a ‧ dul ‧ ter ‧ ate /əˈdʌltəreɪt/ BrE AmE verb [transitive]
[ Date: 1500-1600 ; Language: Latin ; Origin: past participle of adulterare , from ad- 'to' + alter 'other' ]
to make food or drink less pure by adding another substance of lower quality to it ⇨ unadulterated
—adulteration /əˌdʌltəˈreɪʃ ə n/ noun [uncountable]