Lo hizo por envidia: He did it for (out of) envy.

3. To denote equivalency of any kind, as—

Cinco peniques por libra: Fivepence for a pound—per pound.

Trocar un producto por otro: To exchange one product for another.

Considerar á uno bueno por £1,000: To consider somebody as good for £1,000.

Por mejor le envié yo como viajante: I sent you to travel, holding you for a better man.

Tienda por tienda, prefiero esta: Of the two shops I prefer this.

4. To denote distribution, as—

Vinieron cinco por cinco: They came five by five.

=Para= is used—