Pescetarianism is a see also of flexitarianism.

As nouns the difference between pescetarianism and flexitarianism

is that pescetarianism is pescetarianism is a dietary choice in which a person, known as a pescetarian, eats any combination of vegetables, fruit, nuts, beans and fish or seafood, but will not eat mammals or birds some animal products like eggs and dairy may or may not be part of a pescetarian diet plan while flexitarianism is (us) the practice of eating mainly vegetarian food, but making occasional exceptions for social, pragmatic, cultural, or nutritional reasons.