Die-hard and Hard hat

Die-hard adjective - Tending to favor established ideas, conditions, or institutions.

Hard hat and die-hard are semantically related. In some cases you can use "Hard hat" instead the phrase "Die-hard" as a noun or an adjective.

Hard hat noun - A lightweight protective helmet (plastic or metal) worn by construction workers.

Die-hard and hard hat are semantically related. Sometimes you can use "Die-hard" instead the phrase "Hard hat" as a noun or an adjective.