an entrance door for excluding drafts from the interior of a building, usually consisting of four rigid leaves set in the form of a cross and rotating about a central, vertical pivot in the doorway.
2.
Informal.
a.
a company, institution, or organization with a high turnover of personnel or members.
b.
a legal, medical, or other system or agency that discharges criminals, patients, etc., in the shortest possible time and without adequate attention or consideration.
