Indulging in evil activity, which leads the Jīva (soul) to degradation; for example, prāṇātipāta (injuring or killing a living being) etc...
pāpaṃ karma adhaḥpatanakāritvāt pāpaṃ, kriyata iti karma, taccāṣṭādaśavidhaṃ prāṇātipātamrsāvādādattādānamaithunaparigrahakrodhamānamāyālobhapremadveṣakalahābhyākhyāna-paiśunyaparaparivādaratyaratimāyāmṛṣāmithyādarśanaśalyākhyamiti, evametat pāpamaṣṭādaśabhedam.
(ĀVṛ Pa 72)