French word dico comes from French dictionnaire, French -o

Detailed word origin of dico

Dictionary entry	Language	Definition
dictionnaire	French (fra)	(computing) dictionary, an associative array. Dictionary: a list of words, usually arranged alphabetically and presented with definitions or translations.
-o	French (fra)	Added to a noun or an adjective after apocope, to create a familiar synonym.
dico	French (fra)	(informal) dictionary.

Words with the same origin as dico