as in to plunge
to cast oneself head first into deep water
when a wave hit the float, I lost my balance and pitched into the lake

as in to throw
to send through the air especially with a quick forward motion of the arm
pitched the baseball almost 50 feet

as in to sway
to make a series of unsteady side-to-side motions
the ship pitched in the choppy sea

as in to dump
to get rid of as useless or unwanted
we decided to pitch that whole system and start over again

the degree to which a sound or a musical note is high or low:
The piano and organ were tuned to the same pitch.

pitch.