rirxe -ri'e- gismu

x1 is a river of land mass x2, draining watershed x3 into x4/terminating at x4.

(cf. flecu, senta for most metaphorical aspects; daplu, djacu, lalxu, xamsi, rinci, naxle)

In notes:

daplu
x1 is an island/atoll/key of [material/properties] x2 in surroundings/body x3; x1 is insular.
djacu
x1 is made of/contains/is a quantity/expanse of water; (adjective:) x1 is aqueous/[aquatic].
flecu
x1 is a current/flow/river of/in x2 flowing in direction to/towards x3 from direction/source x4.
lalxu
x1 is a lake/lagoon/pool at site/within land mass x2.
naxle
x1 is a canal/channel to x2 from x3 with route x4.
rinci
x1 liquid/fluid drains/strains/flushes from source x2 through drain/strainer x3 by force x4.
senta
x1 is a layer/stratum [shape/form] of x2 [material] within structure/continuum/composite x3.
xamsi
x1 is a sea/ocean/gulf/[atmosphere] of planet x2, of fluid x3; (adjective:) x1 is marine.
cmari'e
r1 is a creek/stream in land mass r2, draining watershed r3 into r4/terminating at r4.
cmatceri'e
r1=cmal1 is a rivulet on surface/terrain r2 draining r3 terminating at r4 small by standard cmal3.
jaclu'a
p1 is a waterway to p2 from p3 via/defined by points including p4 (set).
ri'erkoi
k1 is a bank of river k3=r1.
ri'erxi'a
x1 is a hippopotamus of genus/species x2.
braxas
Ocean
rirx
River
xas
Sea