Adharma is the opposite of Dharma, Apaddharma is Dharma in a dilemma.
Virtue, ethics, morality, dignity. Fulfillment of duty in all areas of life. A husband has different responsibilities than a daughter. A baker has different duties than a shoemaker. A young person has different duties than an old one.
The progenitor of mankind, Manu, wrote the Manu Smriti, the ‚law book of mankind‘. There are ten dharmas
Sanatana Dharma (the eternal law), Samanya Dharma (general duties), Visesha Dharma (individual duties), Varnashrama Dharma (duties of caste (varna) and stages of life (ashrama)), Svadharma (personal duties), Yuga Dharma (duties according to the current yuga), Kula Dharma (duties of a family), Manava Dharma (duties of mankind), Purusha Dharma (duties of a man), Stri Dharma (duties of a woman), Raja Dharma (duties of a regent), Praja Dharma (duties of the people), Pravritti Dharma (duties in worldly life), Nivritti Dharma (duties in spiritual life).
Read Manusmriti here