The term DIAMOND MAKEUP is a combination of two words, 'DIAMOND' and 'MAKEUP'. Diamonds are precious stones that have been used for centuries in jewelry and other decorative items. MAKEUP is a form of cosmetic artistry that is used to enhance the appearance of the face and body. The crossword solution for this term is CARBON, which is an element found in diamonds and MAKEUP. Carbon is a non-metallic element that is essential for life on Earth and is also used in many industrial processes.