(v): hang (back) or fall (behind) in movement, progress, development, etc.
(v): go after with the intent to catch
(v): follow in or as if in pursuit
(v): move, proceed, or walk draggingly or slowly
(v): change location; move, travel, or proceed, also metaphorically
(v): hang down so as to drag along the ground
(v): drag loosely along a surface; allow to sweep the ground
(v): pull, as against a resistance
(n): a track or mark left by something that has passed
(n): a line or route along which something travels or moves
(n): a path or track roughly blazed through wild or hilly country
(n): any road or path affording passage especially a rough one
(n): evidence pointing to a possible solution
(n): your basis for belief or disbelief; knowledge on which to base belief
In glassmaking, a strand of glass, roughly circular in section, drawn out from a gather. Trailing is the process of applying trails as decoration on the body, handle, or foot of a vessel by laying or winding softened threads on it during production.
Cool stuff! So there must be a whole list (hint) of commands for the 18th-century Art of Blowing Up S***.
In an archaic military sense, the hinder end of the stock of a gun-carriage, which rests or slides on the ground when the carriage is unlimbered. When moving the gun by hand, the gun crew is ordered to lift with the command "Up trail!" (or trails) and to let the gun trail rest with the command "Down trail!"