interpair

As a noun terms

is .

As an adjective interpair is

between pairs.

As a noun pair

is two similar or identical things taken together; often followed by of.

As a verb pair

is to group into sets of two or pair can be (obsolete) to impair.

As an adjective interpair is

between pairs.

As adjectives the difference between interpair and intrapair

is that interpair is between pairs while intrapair is within a pair.