To retrace one's steps.
To exercise a racehorse around the racetrack in the opposite direction to that in which races are run.
To taxi down an active runway in the opposite direction to that being used for takeoff.
To repeat or review work already done.
the act of backtracking
To turn or fold inwardly.
To fold inward to create a hollow space where none had existed, as with a gastrula forming from a blastula.
To fold up or enclose into a sheath-like or pouch-like structure, either naturally or as part of a surgical procedure.
Having one portion of a hollow organ drawn back within another portion.
sheathed