Be a mass of Definition 1 of 2Pro Tip 1/3Physical State Used to describe a tangible state of something being overwhelmed by a substance. The kitchen was a mass of smoke after the meal was burnt. Pro Tip 2/3Figurative Use Can also express the idea of something being figuratively filled with nonphysical things. Her mind was a mass of conflicting thoughts. Pro Tip 3/3Negative Connotation Often implies a negative situation, such as disorder or excess. His desk was a mass of useless papers and junk.