What does hulled mean
a hull is the outer covering of a fruit or seed and it's usually fibrous. Something "hulled" has this outer covering removed
It can mean both having the hull still on the grain (as in hulled vs hull-less oats) and having the hull removed from the grain (as in this grain has been hulled).
The first meaning is usually used in agricultural setting (have a look at a seed catalogue that deals with grains like barley and oats, you'll see what I mean), and the second in culinary and when buying grain in the supermarket (although supermarket brands do sometimes confuse the two meanings of the word). But there is some crossover, so whenever possible, double check with the person telling you which they are talking about.