negligent, careless, or slow in performing one's duty, business, etc.

He's terribly remiss in his work.

characterized by negligence or carelessness.

lacking force or energy; languid; sluggish.

adjective

careful , mindful , scrupulous , thorough , thoughtful

adjective

any old way , any which way , asleep at switch , asleep on job , behindhand , culpable , daydreaming , defaultant , delinquent , derelict , dilatory , disregardful , fainant , forgetful , heedless , inattentive , indifferent , indolent , lackadaisical , lax , lazy , neglectful , negligent , regardless , slack , slapdash , slipshod , sloppy , slothful , slow , tardy , uninterested , unmindful , woolgathering