Assiduous adj. 1. Constant in application or attention; diligent: “An assiduous worker who strove for perfection.” 2. Unceasing; persistent: “Assiduous cancer research.”

Precarious adj. 1. Dangerously lacking in security or stability: “The precarious life of an undercover cop.” 2. Subject to chance or unknown conditions. 3. Based on uncertain, unwarranted, or unproved premises. “A precarious solution to a difficult problem.”

Guile n. Treacherous cunning; skillful deceit. Particular skill and cleverness in tricking or deceiving people. “Considerable guile was involved in the transaction.”

Obtuse adj. 1. Lacking quickness of perception or intellect. 2. Characterized by a lack of intelligence or sensitivity. “An obtuse remark.” 3. Not distinctly felt. “An obtuse pain.”

Intrepid adj. 1. Resolutely courageous; fearless. Persistent in the pursuit of something. “A team of intrepid explorers.”

Acrimonious adj. 1. Bitter and sharp in language or tone; rancorous: “An acrimonious debate between the two candidates.”

Demure adj. 1. Modest and reserved in manner or behavior. “Despite her demure appearance, she is an accomplished mountain climber.”

Divisive adj. Creating dissension or discord; Causing disagreement or hostility within a group so that it is likely to split. “Divisive politics.”

Pervasive adj. Having the quality or tendency to pervade or permeate. “The pervasive odor of garlic.”

Benevolent adj. 1. Charitable: performing good or charitable acts and not seeking to make a profit. 2. Characterized by or suggestive of doing good; showing kindness or goodwill.