Adjective.
Given to larceny, tending to thievery. Resembling theft, often applied to legal actions that seem unfair. “These late fees are larcenous. I should have read the fine print before signing.” – Wiktionary.org
Having the character of larceny; as a “larcenous taking.” Contemplating or intending larceny; as a “larcenous purpose.” – Black’s Law Dictionary, 2nd Edition (1910)