Deisal's opposite, moving in the counter-sunwise direction, carried the mirror-image meaning across the same body of Gaelic tradition: unlucky, disrespectful and in some recorded contexts actively dangerous, something one avoided doing around a sacred well, a church, or a house one wished well. The English word widdershins, meaning "in a direction contrary to the sun's course," entered the language via Scots from the same conceptual pairing, and its survival as an ordinary English word for "counter-clockwise," stripped of most speakers' awareness of its ritual origin, is itself evidence of how deeply the sunwise and counter-sunwise distinction had worked its way into everyday Gaelic and, through Scots, wider British habits of thought and speech.
Because deisal is documented continuously from early medieval legal and religious sources through nineteenth and twentieth century folklore collection, it offers historians of Celtic religion a rarer case than most: a specific ritual gesture traceable across the entire span from pre-Christian attestation to modern ethnographic record, in contrast to practices known only from a single early source or reconstructed largely by analogy. Scholars caution, correctly, against assuming later recorded forms of deisal preserve pre-Christian belief unchanged, since the custom clearly absorbed Christian reinterpretation over the centuries, but the underlying gesture and its directional logic show unusually strong continuity even by the standards of Celtic religious material generally, which survives mostly in fragments filtered through Roman and later Christian authors.