glib
     adj 1: marked by lack of intellectual depth; "glib
            generalizations"; "a glib response to a complex
            question"
     2: having only superficial plausibility; "glib promises"; "a
        slick commercial" [syn: {pat}, {slick}]
     3: artfully persuasive in speech; "a glib tongue"; "a
        smooth-tongued hypocrite" [syn: {glib-tongued}, {smooth-tongued}]
     [also: {glibbest}, {glibber}]
Source: WordNet® 2.0