ph

Century Dictionary and Cyclopedia

1. n. A consonant digraph having the sound of ƒ, used in the Latin or English, French, etc., transliteration of Greek words containing φ, as in phalanx, philosophy, graphic, zephyr, etc., or occasionally of words from other languages. It rarely occurs in words other than those of the classes mentioned, and then only by error or confusion, as in triumph, nephew, cipher, ouph, gulph (obsolete) (from a Greek word with π), in words having a similar aspirated p. as in seraph, pamphlet, etc., and obsolete misspellings like phane for fane, prophane for profane, pheer for feer, pheeze for feeze, phiph for fife, etc. In older English words of Greek origin the letter was usually represented by ƒ, as in fancy, fantasy, fantom, fenix, etc., some of these being now spelled with ph, as phantom, phenix, etc.

Wiktionary

1. abbr. common misspelling of pH.

WordNet 3.0

1. n. (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)