\Fore"lock`\, n.
1. The lock of hair that grows from the forepart of the head.
2. (Mech.) A cotter or split pin, as in a slot in a bolt, to
   prevent retraction; a linchpin; a pin fastening the
   cap-square of a gun.
{Forelock bolt}, a bolt retained by a key, gib, or cotter
   passing through a slot.
{Forelock hook} (Rope Making), a winch or whirl by which a
   bunch of three yarns is twisted into a standard. --Knight.
{To take} {time, or occasion}, {by the forelock}, to make
   prompt use of anything; not to let slip an opportunity.
         Time is painted with a lock before and bald behind,
         signifying thereby that we must take time by the
         forelock; for when it is once past, there is no
         recalling it.                         --Swift.
         On occasion's forelock watchful wait. --Milton.