Mart.

Proper noun

 * 1) * 1892, Richard Stanton, A Menology of England and Wales..., p. 645:
 * In the Mart. of Donegal, this is the day of St. Comgall (Comhgall), placed in the Menology on the 27th June, as having no day.
 * 1) * 1892, Richard Stanton, A Menology of England and Wales..., p. 645:
 * In the Mart. of Donegal, this is the day of St. Comgall (Comhgall), placed in the Menology on the 27th June, as having no day.

Usage notes
This is the customary abbreviation of this term as used in case citations. See, e.g., The Bluebook: A Uniform System of Citation, Nineteenth Edition (2010), "Geographical Terms: Foreign countries and regions", Table T10.3, p. 438-443.

Noun

 * 1)  Tue.