Hard-core and Hard line

Hard-core adjective - Firmly established over time.

Hard line and hard-core are semantically related In some cases you can replace phrase "Hard line" with "Hard-core", this phrases are similar.

Hard line noun - A firm and uncompromising stance or position.

Hard-core and hard line are semantically related in firm topic. Sometimes you can use "Hard-core" instead an adjective phrase "Hard line", if it concerns topics such as steadfast, stubborn, serious.