neoblast

1. (biology) A large, undifferentiated cell of annelid worms that participate in regeneration of lost parts.Examples: "To trigger neoblast proliferation and differentation,^([sic]) two days head and tail regenerating animals were used for the preparation of the libraries."

2. (geology) A crystal or mineral species in metamorphic rock, formed more recently, by recrystallization, than others in the same rock.Examples: "Based on insight from large neoblast growth in terrestrial settings, we suggest that the ca. 4.33 Ga neoblasts recently reported in lunar zircon may imply a major basin-forming event on the Moon at that time."