patfu -paf-pa'u- gismu

x1 is a father of x2; x1 begets/sires/acts paternal towards x2; [not necessarily biological].

See also mamta, rirni, rorci, tarbi, dzena, famti, panzi, bersa, sovda.

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].
panzi
x1 is a [biological] offspring/child/kid/hybrid of parent(s) x2; (adjective:) x1 is filial.
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.
sovda
x1 is an egg/ovum/sperm/pollen/gamete of/from organism [mother/father] x2.
tarbi
x1 is an embryo/zygote/fetus/fertilized egg with mother x2, and father x3.
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].
dai'i (exp!)
attitudinal modifier: supposed emotion - factual emotion
paf
Dad