Bottom Chord - The bottom members of a truss.
Bottom Chord Splice - If the truss Span is too long for two Bottom Chords, the middle Bottom Chord is referred to as the splice.
Butt Cut - A small 90 degree cut at the end of a truss - usually 1/4".
Heel Height - The "thickness" of a truss at the end of the Bottom Chord. Measured from the bottom of the Bottom Chord (or top of top plate) to the top of the Top Chord (underside of sheathing) at the end of the truss.
Overall Height - A vertical measurement taken at the midpoint of a truss from the bottom of the Bottom Chord to the peak.
Overhang - The horizontal distance measured from the end of the Bottom Chord (butt cut) to the end of the tail, not including the fascia. If the wall is cantilevered the measurement is from the outside of the wall to the end of the tail. Click How to Match an Existing Roof for more details on cantilever.