As nouns the difference between physa and phyma
is that physa is (zoology) any of the genus (taxlink) of freshwater snails while phyma is (medicine) a tubercle on any external part of the body.
physa
English
Noun
(
en-noun)
(zoology) Any of the genus (taxlink) of freshwater snails.
(
Webster 1913)
phyma
English
Noun
(
en-noun)
(medicine) A tubercle on any external part of the body.
(
Webster 1913)