Untendered rhymes with:
tendered, engendered, rendered, surrendered, tendered, blundered, engendered, floundered, foundered, gerrymandered, hindered, laundered, meandered, nonstandard, pandered, plundered, pondered, rendered, slandered, squandered, standard, substandard, surrendered, tendered, thundered, unhindered, wandered, wondered