"designate as worthy of priority," by 1967 in U.S. government jargon, apparently popularized during the 1972 U.S. presidential contest, from root of priority + -ize. "A word that at present sits uneasily in the language" [OED, 1989]. Related: Prioritized; prioritizing.
Sen. Pete Dominick (R-Colo.) claims that it took him and his staff almost six years (Dominick is up for election next year) just to learn "governmentalese." He notes words such as "generalizationable" and "prioritize" and other words constructed with liberal use of hyphens: "quasi-pseudo-anti-regionalism" and "multi-duplex-co-establishment." [Don MacLean, "Washington Watch" newspaper column, February, 1967]