Olivaceous is an adjective used to describe a dark, yellowish-green color. Some synonyms for this word include olive, olive-green, khaki, and mossy. These words all describe a similar shade of green that is often associated with natural colors found in trees, plants, and other vegetation. Other similar words that could also be used include sage, forest, and hunter green. These shades of green are often used in fashion and interior design to create a calming and earthy atmosphere. Overall, olivaceous is a word that can be interchanged with other green shades to add depth and texture to language and design.