n.1 the expulsion of a foetus (naturally or esp. by medical induction) from the womb before it is able to survive independently, esp. in the first 28 weeks of a human pregnancy.
2 a stunted or deformed creature or thing.
3 the failure of a project or an action.
4 Biol. the arrest of the development of an organ.
Etymology: L abortio (as ABORT)