Prolific descends from Medieval Latin prōlificus, meaning 'offspring-making,' built from Latin prōlēs (offspring, from prō- + alere 'to nourish') and -ficus (making, from facere). It originally described biological fecundity before expanding to mean abundantly creative or productive in any domain.
Producing abundant works, results, or offspring; highly productive or fruitful.
From French 'prolifique,' from Medieval Latin 'prōlificus' (generating offspring), a compound of Latin 'prōlēs' (offspring, progeny) and '-ficus' (making, producing), from 'facere' (to make, to do), from PIE *dʰeh₁- (to put, to place, to make). The element 'prōlēs' itself decomposes into 'prō-' (forth, forward) and 'alere' (to nourish, to feed), from PIE *h₂el- (to grow, to nourish) — the same root that produced 'aliment,' 'alumni' (one who is nourished), and 'adolescent' (growing up). So 'prolific' literally means 'making offspring' or 'producing that which is nourished forth.' The word entered English
The Latin root prōlēs (offspring) also gave us 'proletariat' — in ancient Rome, the prōlētāriī were citizens too poor to serve the state with property; their only contribution was their children. So prolific and proletariat are siblings: one celebrates abundant production, the other was originally a label for those whose only abundance was biological.