Example sentences:

Ramayana: The sage Vishvamitra was a forest-dwelling hermit; his activities were largely extramural and thus his visit to Ayodhya was a surprise to everyone. 

 Mahabharata: The way Ekalavya learned archery was not entirely extramural; though he was not admitted into Drona’s academy, he secretly observed the lessons taught there and took inspiration from Drona’s effigy. 

 Bhagavad-gita: The cultivation of devotion requires association more than seclusion; whether that association is institutional or extramural depends on time-place-circumstance.