Regardless \Re*gard"less\, a. 1. Having no regard; heedless; careless; as, regardless of life, consequences, dignity. Regardless of the bliss wherein he sat. --Milton. 2. Not regarded; slighted. [R.] --Spectator. Syn: Heedless; negligent; careless; indifferent; unconcerned; inattentive; unobservant; neglectful. -- {Re*gard"less*ly}, adv. -- {Re*gard"less*ness}, n.