Indo-Iranian and Indo-European language

Indo-Iranian noun - The branch of the Indo-European family of languages including the Indic and Iranian language groups.

Indo-European language and Indo-Iranian are semantically related. In some cases you can use "Indo-European language" instead a noun phrase "Indo-Iranian".

Indo-European language noun - The family of languages that by 1000 BC were spoken throughout Europe and in parts of southwestern and southern Asia.

Indo-Iranian and Indo-European language are semantically related. Sometimes you can replace phrase "Indo-Iranian" with "Indo-European language", this phrases are similar.