Assassin adjectives are listed in this post. Each word below can often be found in front of the noun assassin in the same sentence. This reference page can help answer the question what are some adjectives commonly used for describing ASSASSIN.
alleged, be, chief, cowardly
dead, first, foul, hired
lone, other, paid, political
potential, professional, real, second
secret, trained, unknown, vile
Hope this word list had the adjective used with assassin you were looking for. Additional describing words / adjectives that describe / adjectives of various nouns can be found in the other pages on this website.
bloodthirsty
merciless when it kills