Furtive
Hidden, secretive
Prosaic
Lifeless, uninspired
Vitriolic
Spiteful, bitter
Anomaly
Irregularity, oddity
Congregation
Faithful, believer
Maudlin
Tearful, sentimental
Ingenious
Intelligent, creative
Vehement
Forcible, spirited
Guile
Craft, artifice
Obdurate
Stubborn, unyielding
Arboreal
Related to trees
Propitious
Auspicious, promising
Congruity
Harmony, appropriateness
Reprobate
Villain, rogue
Ineffable
Marvelous, wonderful