The definition of mesotrophic is a lake or pond that has a moderate amount of plants.
An example of a mestrophic body of water is one with neither an overabundance or a lack of plants.
designating or of a lake, pond, etc. having a moderate amount of plant growth: the mesotrophic stage is intermediate between the oligotrophic and eutrophic stages
(comparative more mesotrophic, superlative most mesotrophic)