N-, mag- -an (repet.) mag- redup. (repet.)
To move back and forth, to wag (of a dog’s tail); writhe (like a snake); wriggle.
Side to side or above and below (a line) or from side to side as a fish’s tail when swimming.
The tail of the dog is wagging.
The tail of a fish is moving back and forth when swimming.
When you are sitting down don’t keep wriggling.
When I write (my writing) moves above and below (the line).