adjective [ usually before noun ]
1.
( of a person ) having very fixed beliefs and being unlikely or unwilling to change them :
a hard-line Communist
2.
( of ideas ) very fixed and unlikely to change :
a hard-line attitude
► hard·liner /ˌhɑ:dˈlaɪnə(r); NAmE ˌhɑ:rd-/ noun :
a Republican hardliner