rirni -rir- gismu

x1 is a parent of/raises/rears x2; x1 mentors/acts parental toward child/protege x2.

See also rorci, mamta, patfu, sidju, dzena, famti, verba, bersa.

In notes:

bersa
x1 is a son of mother/father/parents x2 [not necessarily biological].
dzena
x1 is an elder/ancestor of x2 by bond/tie/degree x3; x1's generation precedes x2's parents.
famti
x1 is an aunt/uncle of x2 by bond/tie x3; x1 is an associated member of x2's parent's generation.
mamta
x1 is a mother of x2; x1 bears/mothers/acts maternally toward x2; [not necessarily biological].
patfu
x1 is a father of x2; x1 begets/sires/acts paternal towards x2; [not necessarily biological].
rorci
x1 engenders/procreates/begets x2 with coparent x3.
sidju
x1 helps/assists/aids object/person x2 do/achieve/maintain event/activity x3.
verba
x1 is a child/kid/juvenile [a young person] of age x2, immature by standard x3.
mamspe
x1 is a step-parent via the mother of x2 due to marriage with the latter's mother according to law/custom x3, where said motherhood is not necessarily biological.
pa'uspe
x1 is a step-parent via the father of x2 due to marriage with the latter's father according to law/custom x3, where said fatherhood is not necessarily biological.
rirbau
b1 is the native language/"mother tongue" of b2=r2
rirny'utka'au
x1 is direct ancestor/mentorial-ancestor of x2 of order x3 (li; nonnegative integer) in graph/network of ancestry (family tree) x4 (defaults to maximal option), where x3 is the smallest possible number which is so constrained; x1 is the x3th-great-grandparent of x2.
rirspe
x1 is the step-parent/step-mother/step-father of x2 due to marriage with their parent according to law/custom x3.
rirtaitra
x1 patronizes x2; x1=t1=r1 acts towards x2=t2=r2 by doing x3=t3 as if x1 was x2's parent.
selrirni
x2=r1 is a parent of/raises/rears x1=r2; x2=r1 mentors/acts parental toward child/protege x1=r2.
teryrorci
x3=r1 engenders/procreates/begets x2=r2 with coparent x1=r3.
paznu
x1 is a non-binary offspring/child of parent(s) x2 [not necessarily biological]; x1 is filial (but not a son or daughter).
preri
x1 is a non-binary parent of x2 [not necessarily biological].
ko'orsi
x1 (ka, binary predicate) links x2 and x3, and x3 and x4, and x4 and x5, et cetera