The first element probably is cognate with Old English haga “enclosure, portion of woodland marked off for cutting” (see hedge (n.)). Old Norse had tunriða and Old High German zunritha, both literally “hedge-rider,” used of witches and ghosts. The second element in the prehistoric compound may be connected with Norwegian tysja “fairy; crippled woman,” Gaulish dusius “demon,” Lithuanian dvasia“spirit,” from PIE *dhewes- “to fly about, smoke, be scattered, vanish.”
https://www.etymonline.com/word/hag
Hag or Hedge-rider
HE Hag or Hedge rider. Usually old and ugly women were depicted. Let’s see what’s the story behind the original meaning. In the old settlements often a hedge was planted, hedges usually had thorns, so crossing a hedge would mean that you would get hurt, so animals, like wolves and foxes, would stay outside. A hedge could, for example, be a blackthorn, and a blackthorn has magical qualities. Both berries and leafs are commonly used in protection- and counter-curse-magic 1).
The hedge also has another meaning: it is a portal to the nether-world. We often go into a trancelike state, known as ‘the becoming’. This is somewhat difficult to explain, because there are many steps involved, like ‘gathering sprouse’ or gathering the energy of the Red Serpent 2). In Traditional Witchcraft it is not an easy task, a hobby or something you learn overnight.
That’s why a Hag is often depicted as an old woman, because it takes years of learning in silence 3) and of course the ins and outs are not out in the open. Traditional Witchcraft is powerful in the hands of an accomplished witch, you are not wise to share knowledge that could mean (self)destruction for people with a false and enlarged ego. Don’t share a recipe for a bomb, that could mean innocent people to get killed by a fool.
So, images of an old woman, associated with a hag is not without a reason. Nothing is easy and comes overnight. That’s a big difference with forms of witchcraft that are out in the open and have different rules. What kind of traditional magic, whether it be Traditional Witchcraft, Seiðr Magic 4), Shamanism, Voodoo/Hoodoo, Guna Guna or other forms, all take time and secrecy. That’s why I only share the upper surface, without going into details. By the way: a traditional witch is a specialist, not a blind follower. We ride the hedge…

Notes
1 ) A Pellar is a Cornish term for a witch, specialized in counter-curses. Since a curse or hex is often a very complicated thing, the pillar first determines what method of hexing is used, the witch that caused the hex and to provide a solution or a ‘return to sender’ counter-spell. This is a delicate process and not an easy task. On the Internet we can find ‘one size fits all’ spells, but this is bogus. It takes years of practice and often a mentor guiding you. I’ve you were raised in traditional witchcraft you are taught how to act in specific situations. You cannot learn it from spell books only. That’s why is takes years of decennia to become an accomplished and specialized pellar.
2) A very useful book is ‘ Traditional Witchcraft, a Cornish Book of Ways‘ by Miss Gemma Gary, ISBN 0956104347. You can order is from Troy Books UK.
3) Another great book is Silent as the Trees by Miss Gemma Gary, about Devonshire Witchcraft.
4) Old Scandinavian Magic, see: https://vikingr.org/magic-symbols/seidr
and the Youtube channel of Freyia Norling.
