infant star noun2 •A newly formed star; a star that has just begun to sustain a fusion reaction.Perhaps thy sight is wandering far Throughout the kindled sky, In tracing every infant star Amid the lights on high, — 1849 •Synonym of protostar.Eventually, the energy released by the collapsing material raises the temperature in the core of an infant star enough to ignite self-sustaining nuclear reactions. — 1983 formsinfant stars