L remissus (ptp. of remittere to send back, slacken, relax)
1. negligent, careless, or slow in performing one's duty, business, etc.: He's terribly remiss in his work.
2. characterized by negligence or carelessness.
3. lacking force or energy; languid; sluggish.
derelict, thoughtless, lax, slack, neglectful. dilatory, slothful, slow
Last week Jessica was remiss in posting on her assigned day