volunteerism (n.)

c. 1600, "one who offers himself for military service," from French voluntaire, "one who volunteers," also as an adjective, "voluntary," from Latin voluntarius "voluntary, of one's free will," as a plural noun "volunteers" (see voluntary). Non-military sense is first recorded 1630s. As an adjective from 1640s. Tennessee has been the Volunteer State since the Mexican War, when a call for 2,800 volunteers brought out 30,000 men.

word-forming element making nouns implying a practice, system, doctrine, etc., from French -isme or directly from Latin -isma, -ismus (source also of Italian, Spanish -ismo, Dutch, German -ismus), from Greek -ismos, noun ending signifying the practice or teaching of a thing, from the stem of verbs in -izein, a verb-forming element denoting the doing of the noun or adjective to which it is attached. For distinction of use, see -ity. The related Greek suffix -isma(t)- affects some forms.