Interfirm is an adjective. The adjective is the word that accompanies the noun to determine or qualify it.

What does interfirm mean?

: occurring between or involving two or more firms interfirm transactions …

What does interfirm cooperation mean?

Definition. Inter-firm cooperation (IFC) can be defined as quasi-stable, durable, formal or informal arrangements between two or more independent firms, aiming to further the perceived interests of the parties involved.