[Scottish Gaelic ( Gàidhlig ) word] southward, sun-ward, Early Irish dessel; from deas (right, south) and sel (*svel), Welsh chwyl. See also deas and seal.
Also means "ready", "handy (dexterous)", and "finished".
( tha mi deiseil: I am finished.)
(Fhuair e deiseil agus chuir e am fàinne òir 'na phòca.)
Deiseil [Scottish old customs] : to circle three times clockwise (sunwise); don a cow hide; stop at the threshold of each of house .
"To walk deiseil" (according to modern references) means to walk in a circle with the sun; from east, towards the south, to west, to north, back to east.
"Deasil, from the Gaelic "deiseil", meaning "to turn to the right", refers to clockwise motion, or more to the point, motion in tune with the motion of the sun. "
According to Guth na Gàidhlig:
>" The variant deiseil is a later variation of deas, from Lewis and Uist (the Outer Hebrides, islands of the west coast of Scotland)."
>" The word deas (right) is actually related to the Latin word dexter (via dess in Old Irish), and has dexters positive nuances
> (dexterous, skillful, expert, proper, fit, pretty, handsome, trim, active).
> Other words for "right" also have these positive nuances.
> Thus ceart means right in a directional sense, but also right as in correct, as well as just, honest, upright, proper, certain, and
> fair. By the way, the traditional way of asking Are you ready? is Am bheil thu deas?.
also Deosil/ Deasil (English)
[folklore}: DEISEIL: A very common practise is the circling three times deiseil, or sunwise, of a certain place, house etc., to bring good luck and fortune. This is clearly a pagan custom of drawing down the power of the sun, associated with blessings, good health and fortune. For example, fire is carried three times around an infant; boats are rowed three times sunwise before a journey; the sick circle three times around a holy well for health.
Fhuair e deiseil agus chuir e am fàinne òir 'na phòca.
Scottish Gàidhlig: Lesson 23 (includes sound file to hear pronunciation)
 Deasil go by the waxing moon, Singing out the Witches' Rune.