"action of blocking up a way or passage, act of impeding passage or movement; fact of being obstructed," 1530s, from Latin obstructionem (nominative obstructio) "an obstruction, barrier, a building up," noun of action from past-participle stem of obstruere "build up, block, block up, build against, stop, bar, hinder," from ob "in front of, in the way of" (see ob-) + struere "to pile, build" (from PIE *streu-, extended form of root *stere- "to spread"). Figurative use is by 1650s.
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.