Strong solution refers to a concentrated mixture that contains a high amount of a particular substance or chemical. There are several synonyms that can be used to describe a strong solution such as concentrated, potent, powerful, intense, and robust. These words all imply a high degree of strength or effectiveness, which makes them appropriate to use when describing solutions that have a strong chemical composition. Other synonyms include dense, heavy, thick, and rich, which can be used to describe solutions that are more viscous or have a higher density than regular solutions. Ultimately, the choice of synonym will depend on the context and intended meaning of the description.