List of frowning synonyms and frowning related words.
beetle-browed, black, black-browed, dark, decorous, dejected, demure, dour, dumpish, earnest, formal, glowering, glum, grave, grim, grim-faced, grim-visaged, grum, long-faced, lowering, melancholy, moodish, moody, mopey, moping, mopish, morose, mumpish, scowling, sedate, serious, sober, sober-minded, sobersided, solemn, somber, staid, stone-faced, straight-faced, sulky, sullen, surly, thoughtful, unsmiling, weighty