party line

1. 1.

   the policy of a political group

   “He won in a vote along party lines”

   Broaderpolicy
2. 2.

   a telephone line serving two or more subscribers

   Broadertelephone line

Questions about party line

What does party line mean?

party line means "the policy of a political group". That is the primary sense; the word has 2 in total, listed in full on this page.

Is party line a common word?

party line is banded "Uncommon" — turns up in careful writing rather than conversation. The band comes from how often the word appears in a large corpus of everyday English, not from an editor's impression.