The peck is a unit of volume in the US customary unit system. It uses the symbol pk.
1 US peck is equal to 1/4 of a US bushel. This is also equal to 2 US dry gallons, 8 US dry quarts or 16 US dry pints. In SI / metric, this equates to 8.809768 L.
Although the imperial peck is almost obsolete, it survives in some places in the USA - where some products (namely apples) are still sold by the peck.
It appears in the old English nursery rhyme; 'Peter Piper' where he 'picked a peck of pickled peppers'.