(from potential of Hydrogen) the logarithm of the reciprocal of hydrogen-ion concentration in gram atoms per liter; provides a measure on a scale from 0 to 14 of the acidity or alkalinity of a solution (where 7 is neutral and greater than 7 is more basic and less than 7 is more acidic)
a notation used in transcripts to indicate that the transcriber does not know the spelling, usually of a name, and has spelled it as it was pronounced (Initialism of phonetically.)