Pah interj. : An exclamation expressing disgust or contempt. See Bah.

Pah n. : A kind of stockaded intrenchment.

Example:
How can I get bezo[a]pyrene (a Pah) for an experiment? Can I prepare it in a lab or can I just buy some?

Taxonomy
PAHs, benzo, Polycyclic aromatic hydrocarbons, compounds, anthracene, rings, sextets, molecules, fluoranthene, pyrene, aromatic, fossil fuel, aromaticity, isomers, Polycyclic aromatic hydrocarbon, aromatic rings, Chemical compound, free encyclopedia.

Defination from the web:
PAH is insoluble. ... By formal convention, it is not a true PAH, though is referred to as a bicyclic aromatic hydrocarbon. ... Main article: PAH world hypothesis ...