Prior to the arrival of these religions [Islam and Christianity] the Yoruba did not possess a word to describe religiosity as a distinct field of human activity, as something set aside from profane activity. The Yoruba word that was coined in reference to religion was esin, from sin – to serve. This referred to the modes of worship exemplified by Muslims and Christians while the Yoruba themselves were doing asa ibile, meaning, doing the customs of the land.
excerpt from, The invisible city in the realm of mystery
Nicholaj De Mattos Frisvold
(At The Crossroads)
The first pitfall: the Norse sál or sala, “soul” is borrowed from the Old Saxon sala (German, seele; English, soul). This term did not exist in the Norse language, just as, incidentally, the word religion replaced custom (sidr).
Claude Lecouteux (former professor of medieval literature and civilization)
The Return of the Dead: Ghosts, Ancestors, and the Transparent Veil of the Pagan Mind
Personally I lean to the view that paganism was not defined as a body of words and
orthodoxy with set rituals either in Antiquity or in pre-Christian Ireland.
I think there was a traditional grammar of actions that might be performed
perhaps at a particular time or place that seemed significant, or perhaps in
a time of need. I think that votive and thanksgiving offerings were made. I
think there would be a sense of tradition that different communities would
pass down what they thought had worked for them in ensuring good harvests,
good health, etc. and that keeping a piety to tradition was important.