per-

(non-productive) In verbs: denoting the sense "through", as in perforate.

(non-productive) In verbs: denoting the sense "thoroughly", as in perfect.

(non-productive) In verbs: denoting the sense "to destruction", as in pervert.

(non-productive) In adjectives and adverbs: denoting the sense "extremely", as in perfervid.

(chemistry) Forming nouns and adjectives denoting the maximum proportion of one element in a compound, as in peroxide.

(chemistry) Added to the name of an element in a polyatomic ion to denote the number of atoms of that element (usually four).