fluor·i·date 
(flrĭ-dāt′, flôr-)
(flrĭ-dāt′, flôr-)tr.v. fluor·i·dat·ed, fluor·i·dat·ing, fluor·i·dates
To add a fluorine compound to (a drinking water supply, for example) for the purpose of reducing tooth decay.
fluor′i·dation (-dāshən) n.