AKA shedding, woodshedding is one of the most ambiguous jazz terms around (but the version I learned from old time players will be posted here). Sheddin is the act of intensely practicing your instrument after being publicly humiliated by your bad playing. This humiliation might be from a terrible solo or from not knowing the key the piece is played in (not being able to improvise in all keys). Shedding usually includes
This is derived from getting your ass beaten (with scraps from a woodshed).
I went down to a jam session at ----- about a month ago, and this other tenor player just tore my ass UP. So I shedded every day since, and I'm finally confident and able enough to play in public again. Ima tear this shit up, ya heard?! I went down to the woodshed.