As a verb flowest
is archaic second-person singular of flow.
As an adjective flowiest is
superlative of flowy.
flowest
English
Verb
(
head)
(archaic) (flow)
* Elizabeth Barrett Browning
- Thou flowest still, O river,
Thou flowest 'neath the moon.
flowiest
English
Adjective
(head)
(flowy) flowy
English
Adjective
(
er)
flowing; able to flow
-