Pervicacious adj. Stubborn, extremely willful, obstinate. “He became quite pervicacious in his old age.”

Accoutrement n. Additional items of dress or equipment, carried or worn by a person or used for a particular activity. The General dressed for battle in shining accoutrements.”

Vernacular n. The language or dialect spoken by the ordinary people in a particular country or region. An idiomatic word, phrase, or expression. The idiom of a particular trade or profession: “In the legal vernacular.”

Paradigm n. A typical example or pattern of something; a model. “The economic paradigm was flawed.”

Deciduous adj. Not permanent or lasting; ephemeral. “The fire created a deciduous outlook for the company.”

Pedantic adj. 1. Characterized by a narrow, often ostentatious concern for book learning and formal rules. “A pedantic attention to details.”

Vexatious adj. 1. Full of annoyance or distress; harassed. 2. Causing or creating vexation; annoying. “Her ex-husband put her in a vexatioussituation.”

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.”