at·tain / əˈtān/ • v. [tr.] succeed in achieving (something that one desires and has worked for): clarify your objectives and ways of attaining them he attained the rank of admiral. ∎  reach (a specified age, size, or amount): dolphins can attain remarkable speeds in water.DERIVATIVES: at·tain·a·bil·i·ty / əˌtānəˈbilitē/ n.at·tain·a·ble adj.

attain †strike; reach (to). XIV. — OF. atain-, atein-, stem of ataindre, -eindre (mod. atteindre) :- L. attingere touch on, reach, f. AT- + tangere touch.
Hence attainment XIV.