Pitch = frequency of sound. For example, middle C in equal temperament = 261.6 Hz
Sounds may be generally characterized by pitch, loudness, and quality. The perceived pitch of a sound is just the ear's response to frequency, i.e., for most practical purposes the pitch is just the frequency. The pitch perception of the human ear is understood to operate basically by the place theory, with some sharpening mechanism necessary to explain the remarkably high resolution of human pitch perception.
The place theory and its refinements provide plausible models for the perception of the relative pitch of two tones, but do not explain the phenomenon of perfect pitch.
The just noticeable difference in pitch is conveniently expressed in cents, and the standard figure for the human ear is 5 cents.
2a. General. To throw or toss. Antonym: catch.
2b. Colloquially, to dispose of as refuse. "Pitch those worn-out costumes--we'll never use them again."
3. Carpentry. The angle of something. Roof pitch. Out of plumb.
4. Sports. Another term for soccer field.