怠慢 （タイマン） negligence, neglect, carelessness, procrastination

滞納 （タイノウ） falling behind (with a payment), being in arrears, non-payment, default, delinquency

懈怠 （ケタイ） laziness, indolence, negligence (of duties), misfeasance, nonfeasance, negligence, laches, kausidya

休怠 （キュウタイ） laziness, neglect

怠る （おこたる） to neglect, to be negligent in, to be neglectful of, to fail to do, to leave undone, to avoid (doing), to shirk, to be unmindful of, to improve (of an illness), to get better

怠ける （なまける） to be lazy, to be idle, to slack, to neglect (e.g. one's work), to be neglectful of, to skip (e.g. school)