bersa -bes-be'a- gismu

x1 is a son of mother/father/parents x2 [not necessarily biological].

Also filial. See also verba, nanla, nakni, nanmu, patfu, mamta, bruna, rirni, rorci, panzi, tixnu.

In notes:

bruna
x1 is brother of/fraternal to x2 by bond/tie/standard/parent(s) x3; [not necess. biological].
mamta
x1 is a mother of x2; x1 bears/mothers/acts maternally toward x2; [not necessarily biological].
nakni
x1 is a male/buck of species x2 evidencing masculine physical/biological/genetic trait(s) x3 (ka); x1 is masculine.
nanla
x1 is a boy/lad [young male person] of age x2 immature by standard x3.
nanmu
x1 is a man/men; x1 is a male humanoid person [not necessarily adult].
panzi
x1 is a [biological] offspring/child/kid/hybrid of parent(s) x2; (adjective:) x1 is filial.
patfu
x1 is a father of x2; x1 begets/sires/acts paternal towards x2; [not necessarily biological].
rirni
x1 is a parent of/raises/rears x2; x1 mentors/acts parental toward child/protege x2.
rorci
x1 engenders/procreates/begets x2 with coparent x3.
tixnu
x1 is a daughter of mother/father/parents x2; [not necessarily biological].
verba
x1 is a child/kid/juvenile [a young person] of age x2, immature by standard x3.
selbe'a
x2=b1 is a son of mother/father/parents x1=b2 (not necessarily biological).
nonmu
x1 is an agender humanoid person [not necessarily adult].
nunmu
x1 is a non-binary humanoid person [not necessarily adult].
paznu
x1 is a non-binary offspring/child of parent(s) x2 [not necessarily biological]; x1 is filial (but not a son or daughter).
vepre
x1 is a non-binary child/kid/juvenile [a young person] of age x2 immature by standard x3.
ko'orsi
x1 (ka, binary predicate) links x2 and x3, and x3 and x4, and x4 and x5, et cetera
remrnunmu
x1 is a non-binary-gendered humanoid person [not necessarily adult]
bes
Son