What is "to head up"

Head \Head\ (h[e^]d), v. t. [imp. & p. p. Headed; p. pr. & vb. n. Heading.]

1. To be at the head of; to put one's self at the head of; to lead; to direct; to act as leader to; as, to head an army, an expedition, or a riot.
   --Dryden.

2. To form a head to; to fit or furnish with a head; as, to head a nail.
   --Spenser.

3. To behead; to decapitate. [Obs.]
   --Shak.

4. To cut off the top of; to lop off; as, to head trees.

5. To go in front of; to get in the front of, so as to hinder or stop; to oppose; hence, to check or restrain; as, to head a drove of cattle; to head a person; the wind heads a ship.

6. To set on the head; as, to head a cask. To head off, to intercept; to get before; as, an officer heads off a thief who is escaping. ``We'll head them off at the pass.'' To head up,

   1. to close, as a cask or barrel, by fitting a head to.

   2. To serve as the leader of; as, to head up a team of investigators.