When the chin (also known as the beard) turns black it can mean several things. 1) The Bearded Dragon is mad and is warning you to stay away. 2) The Beardie might be basking, as everyone knows black attracts heat. 3) The Beardie might be sick. 4) The Beardie might feel threatened and is trying to protect itself.
2. something used to mark the boundary of land. 3. a building or other place of outstanding historical, aesthetic, or cultural importance. 4. a significant or historic event, juncture, achievement, etc. 5. to declare (a building, site, etc.) a landmark.
prominence(noun) the state of being prominent: widely known or eminent. prominence(noun) relative importance. bulge, bump, hump, swelling, gibbosity, gibbousness, jut, prominence, protuberance, protrusion, extrusion, excrescence(noun) something that bulges out or is protuberant or projects from its surroundings.