1.  legation(n = noun.act) legateship - the post or office of legate;
is a kind of berth, billet, office, place, position, post, situation, spot

2.  legation(n = noun.group) foreign mission - a permanent diplomatic mission headed by a minister;
is a kind of diplomatic mission

1.  The sending forth or commissioning one person to act for another. Bp. Warburton. [1913 Webster]

2.  A legate, or envoy, and the persons associated with him in his mission; an embassy; or, in stricter usage, a diplomatic minister and his suite; a deputation. [1913 Webster]

3.  The place of business or official residence of a diplomatic minister at a foreign court or seat of government. [1913 Webster]

4.  A district under the jurisdiction of a legate. [1913 Webster]

legation, n.
1 a body of deputies.
2 a the office and staff of a diplomatic minister (esp. when not having ambassadorial rank). b the official residence of a diplomatic minister.
3 a legateship.
4 the sending of a legate or deputy.

Etymology:
ME f. OF legation or L legatio (as LEGATE(1))

N  commission, delegation, consignment, assignment, procuration, deputation, legation, mission, embassy, agency, agentship, power of attorney, clerkship, surrogacy, errand, charge, brevet, diploma, exequatur, permit, appointment, nomination, designation, return, charter, ordination, installation, inauguration, investiture, swearing-in, accession, coronation, enthronement, vicegerency, regency, regentship, viceroy, consignee, deputy, agent, delegate, consignee, commissioned, per procurationem.