Pa. [ pɑ:, pɔ: ]
n. an informal term for a father; probably derived from baby talk 同义词：daddadadaddypapapapappapop
a short-lived radioactive metallic element formed from uranium and disintegrating into actinium and then into lead 同义词：protactiniumprotoactiniumPaatomic number 91
a unit of pressure equal to one newton per square meter 同义词：pascalPa
a Mid-Atlantic state; one of the original 13 colonies 同义词：PennsylvaniaKeystone StatePA
an electronic amplification system used as a communication system in public areas 同义词：public address systemP.A. systemPA systemP.A.PA