Celtic language and Indo-European language

Celtic language noun - A branch of the Indo-European languages that (judging from inscriptions and place names) was spread widely over Europe in the pre-Christian era.

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

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

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