bilingualism

From bilingual +‎ -ism.

bilingualism (countable and uncountable, plural bilingualisms)

1. The condition of being bilingual; the ability to speak two languages.
   • 1955 May, Rev. A. W. V. Mace, “An Irish Journey—1”, in Railway Magazine, page 297:

     At Kingsbridge, the bilingualism of the Irish Republic was evident in the tickets, the station notices, and the neat destination boards on the 10.40 a.m. express to Cork.