sol 4 (sɔl, sɒl) n. a fluid colloidal solution. [1885–95] Sol (sɒl) n. 1. a personification of the sun. 2. the Roman god of the sun, identified with the Greek god Helios. -sol. a combining form meaning “soil” of the kind specified by the initial element: spodosol. [< Latin solum soil] Sol. 1. Solicitor. 2. Solomon. sol