(sometimes offensive) A person who is within the boundaries of a political state without the authorization of the government of that state; a national of another country who has entered or stayed without permission.

plural of alien priory

A small religious house dependent on a large monastery in some other country.

(law) A common law tort that can be brought against the third party alleged to be responsible for the failure of marriage; abolished in many jurisdictions.

plural of alien abduction

(botany) A plant that appears with no apparent human assistance but does not develop a sustained population.

plural of casual alien

A supposed disturbance in which children are obsessively preoccupied with depreciation and/or criticism of a parent.

(neurology, psychiatry) A condition in which a person experiences their limbs acting seemingly on their own, without control over the actions.

plural of alien hand syndrome