Tillered - refers to the bend of the limbs-- the shape of the arc. The distance as measured from the limb to the string when the bow is strung, often is slightly different between the upper and lower limb. For example, If you measured from a point at the middle of the upper limb to the string, you likely would find that it is 1/4"-1/2" greater on most bows, than the same measurement taken on the lower limb. This is because the lower limb is made slightly stronger, to compensate for the grip on the string being somewhat lower than center, thus there is going to be more force applied to the lower limb. The idea is to get the limbs to react in unison.
Hey-- Best wishes, and get well soon. Wish I had an extra bow, at the moment, I'd just send it to you. You can find some decent older used ones for 100-$150 -- Nothing wrong with an "experienced bow"-- its the only kind I buy.