gemmule

Meanings

1. Synonym of gemma (“an asexual reproductive structure, as found in animals such as hydra (genus Hydra) and plants such as liverworts (division Marchantiophyta), consisting of a cluster of cells from which a new individual can develop”)
2. A small gemma or bud of dormant embryonic cells produced by some freshwater sponges (phylum Porifera) that develops into a new sponge.
3. In the obsolete theory of pangenesis propounded by the English scientist Charles Darwin (1809–1882): a hypothetical particle once thought to be the basis of heredity.
4. Synonym of plumule (“the first bud, or growing point, of a plant embryo, situated above the cotyledons”).
5. Synonym of dendritic spine (“a small membranous protrusion from the dendrite of a neuron that typically receives input from a single axon at the synapse”).

Etymology

Borrowed from French gemmule, from Latin gemmula (“small bud; small gem”), from gemma (“bud of a plant; gem, jewel; thing made of precious stones”) (further etymology uncertain; possibly from Proto-Indo-European *ǵenh₁- (“to beget, give birth; to produce”), but see further at that entry) + -ula (feminine form of -ulus (diminutive suffix)).