1. Malignity; spitefulness; virulency 
2. Firm establishment by long continuance; firmness or deep-rooted obstinacy of any quality or state acquired by time; as, the inveteracy of custom, habit, or disease; - usually in a bad sense; as, the inveteracy of prejudice or of error

Derived forms: inveteracies

• appreciative
• appreciatively
• appreciativeness
• appreciator
• appreciatory
• apprehend
• apprehended
• apprehender
• apprehensible
• apprehension
• apprehensive
• apprehensively
• apprehensiveness
• apprentice
• apprenticed
• apprenticeship
• appressed
• apprisal
• apprise
• apprize
• appro
• approach
• approach path
• approach pattern
• approach shot