Pb

noun

1. a unit of information equal to 1000 terabytes or 10^15 bytes
2. a soft heavy toxic malleable metallic element; bluish white when freshly cut but tarnishes readily to dull grey"the children were playing with lead soldiers"
3. a unit of information equal to 1024 tebibytes or 2^50 bytes
4. a unit of information equal to 1000 terabits or 10^15 bits