cifnu -cif- gismu

x₁ is an infant/baby [helpless through youth/incomplete development] of species x₂.

Also infantile. See also makcu, verba.

jbovlaste

In notes:

makcu: x₁ is mature/ripe/fully-grown/adult in development-quality x₂ (ka).
verba: x₁ is a child/kid/juvenile [a young person] of age x₂, immature by standard x₃.
ckopalku: p₁ is a diaper (absorbent garment) of material p₂.
remyladru: l₁ is human breast milk/mother's milk from human r₁.
iupna: x₁ is a pupa