1. (n.) The act of giving premature birth; particularly, the expulsion of the human fetus prematurely, or before it is capable of sustaining life; miscarriage.

2. (n.) The immature product of an untimely birth.

3. (n.) Arrest of development of any organ, so that it remains an imperfect formation or is absorbed.

4. (n.) Any fruit or produce that does not come to maturity, or anything which in its progress, before it is matured or perfect; a complete failure; as, his attempt proved an abortion.

Altmann theory DNA De Vries theory Galtonian theory Mendelianism Mendelism RNA Verworn theory Weismann theory Weismannism Wiesner theory abiogenesis abortion accouchement affiliation allele allelomorph ancestry animal spirits animate existence animation apparentation archigenesis aristocracy aristocraticalness babyhood bear bearing beget beginning beginnings being alive biogenesis birth throes birthing blastogenesis blessed event blood bloodline blue blood branch breed bring to birth character childbearing childbed childbirth childhood chromatid chromatin chromosome commencement common ancestry confinement consanguinity cradle creation dawn dawning delivery derivation descent determinant determiner development diathesis digenesis direct line distaff side distinction emergence endowment engender epigenesis eugenics eumerogenesis existence extraction factor family father female line filiation freshman year gene generation genesiology genesis genetic code genetics genteelness gentility give birth to giving birth hatching having a baby having life hereditability heredity heritability heritage heterogenesis histogenesis homogenesis honorable descent house immortality inborn capacity inception inchoation incipience incipiency incunabula infancy inheritability inheritance isogenesis labor life lifetime line line of descent lineage liveliness living long life longevity male line matrocliny merogenesis metagenesis miscarriage monogenesis mother multiparity nascence nascency nativity nobility noble birth nobleness onset opening origin origination orthogenesis outset outstart pangenesis parentage parthenogenesis parturition patrocliny pharmacogenetics phylum pregnancy procreate procreation quality race rank recessive character replication royalty seed sept side sire slip spear side spindle side spontaneous generation spriteliness start stem stirps stock strain succession sword side the Nativity the stork travail viability vitality vivacity youth