предварительный

I

Some high-temperature reactions require the prior dissociation of a molecule to produce ...

By this method functions can be obtained immediately, without first (or previously) solving the differential equations.

Previous cleaning of the metal is required.

II

Some tentative (or preliminary, or provisional) general conclusions from experimental observations can be made.

Источник: Русско-английский научно-технический словарь на Gufo.me