alendronic acid /ˌæl.ənˌdɹɑn.ɪk ˈæs.ɪd/ noun1 •A bisphosphonate C₄H₁₃NO₇P₂ used to inhibit bone resorption especially in the treatment of osteoporosis in postmenopausal women and Paget's disease of bone. Trade names include Fosamax and possibly others.