孳 (w)

(zī) industrious; produce; bear

孳乳 (w)

(zīrǔ) to multiply (kinds, difficulties); to reproduce; to derive (compounds)

孳孳 (w)

(zīzī) diligent; hardworking; industrious; assiduous

孳生 (w)

(zīshēng) to multiply; to breed