brick trowel: a trowel used in masonry
trowel: a small hand tool with a handle and flat metal blade; used for scooping or spreading plaster or similar materials
fatty acid: any of a class of aliphatic monocarboxylic acids that form part of a lipid molecule and can be derived from fat by hydrolysis; fatty acids are simple molecules built around a series of carbon atoms linked together in a chain of 12 to 22 carbon atoms