Definition of "per-" in English

prefix

1. (no longer productive) In verbs: denoting the sense "through", as in perforate.

2. (no longer productive) In verbs: denoting the sense "thoroughly", as in perfect.

3. (no longer productive) In verbs: denoting the sense "to destruction", as in pervert.

4. (no longer productive) In adjectives and adverbs: denoting the sense "extremely", as in perfervid.

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

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

prefix

1. (no longer productive) Denoting the sense "by" or "per", as in perchance or perhaps.