1. (noun)petabyte, PB a unit of information equal to 1000 terabytes or 10^15 bytes Synonyms: petabyte, petabit, lead, atomic number 82, pebibyte
2. (noun)petabyte, pebibyte, PB, PiB a unit of information equal to 1024 tebibytes or 2^50 bytes Synonyms: petabyte, petabit, lead, atomic number 82, pebibyte