blockade n.

"obstruct, hinder passage from or to," 1590s, from French bloquer "to block, stop up," from Old French bloc "log, block of wood" (see block (n.1)). Compare Dutch blokkeren, German blockieren "to blockade." The sense in cricket is from 1772; in U.S. football, "stop or obstruct another player," from 1889. Related: Blocked; blocking.

word-forming element denoting an action or product of an action, via French, Spanish, or Italian, ultimately from Latin -ata, fem. past-participle ending used in forming nouns. The usual form in French is -ée. The parallel form, -ade, came into French about the 13c. via southern Romanic languages (Spanish, Portuguese, and Provençal -ada, Italian -ata), hence grenade, crusade, ballad, arcade, comrade, balustrade, lemonade, etc.

This foreign suffix ade has been so largely imported, and at a time when the French language had still a certain plastic force, that it has been adopted as a popular suffix, and is still employed to form a crowd of new words, such as promenade, embrassade, glissade, bourrade, &c. [Brachet, "Etymological Dictionary of the French Language," Kitchin transl., Oxford, 1882]

Latin -atus, past-participle suffix of verbs of the 1st conjugation, also became -ade in French (Spanish -ado, Italian -ato) and came to be used as a suffix denoting persons or groups participating in an action (such as brigade, desperado).

"detached fort blocking a landing, mountain pass, etc., 1510s, of uncertain origin; perhaps from Middle Dutch blokhuis, German Blockhaus, French blockhaus (which is from one of the German words), all from 16c.; see block (v.1). Later "building with an overhanging upper story with loopholes for firing through" (often a square of logs serving as a fort in rough country), which seems to connect it to block (n.1). For second element, see house (n.).