from Spanish and Portuguese -ado, or refashioning of Italian -ata, Spanish -ada, based on Latin -atus （past participial suffix of verbs ending in -are）.
-ado, suffix of ns.1. a. Sp. or Pg.-adomasc. of pa.pple., as El Dorado the gilded:—L. deaurātus; desperado one out of hope:—desperātus; tornado (Pg.) that which is turned or whirled; renegado one who has re-denied the faith, now renegade.2. An ignorant sonorous refashioning of ns. in -ade, a. Fr.-adefem. (=Sp.-ada, It.-ata) probably after the assumed analogy of renegade=renegado; e.g.ambuscado, bastinado, bravado, barricado, carbonado, camisado, crusado, grenado, gambado, palisado, panado, scalado, stoccado, strappado, all of which in Sp. have (or would have) -ada. So armadoobs.var. of armada.
-ado
in commando, desperado, tornado, and other words of Spanish and Portuguese origin, "person or group participating in an action," from Latin -atus, past participle suffix of verbs of the first conjugation (see -ade).
-ado/ˈeɪdəʊ, ˈɑ:-/suffix.Forming nouns.
1.Repr. Spanish & Portuguese -ado (from Latin -atus-ate2) masc. pa. ppl ending of verbs in -ar, as desperado, tornado.
2.Refash. of French words in -ade (see -ade1), Spanish words in -ada, and Italian words in -ata, as bravado.