"one who rises in revolt" against a government or its laws, 1745, from Latin insurgentem (nominative insurgens), present participle of insurgere "rise up, lift oneself; rise against; stand high, gather force," from in- "against," or here perhaps merely intensive, + surgere "to rise" (see surge (n.)).
An obsolete verb insurge (from French insurger) "to rise in opposition or insurrection" was common 16c. For verb forms 19c. writers sometimes turned to insurrectionize or insurrect.