unadvisable adjective3 •Inadvisable.No steps were taken to enforce it, as, from the financial embarrassment of the company and the uncompleted state of the line, litigation was unadvisable. — 1941 •(no longer used) Imprudent. •(no longer used) Unwilling to take advice.Together with pride there will naturally arise an unadvisable and unconvincible spirit. — 1853 formsmore unadvisable · most unadvisable