Disingenuous

Dis`in*gen"u*ous (?), a. 1. Not noble; unbecoming true honor or dignity; mean; unworthy; as, disingenuous conduct or schemes.

2. Not ingenuous; wanting in noble candor or frankness; not frank or open; uncandid; unworthily or meanly artful.

So disingenuous as not to confess them [faults].
Pope.

-- Dis`in*gen"u*ous*ly, adv. T. Warton. -- Dis`in*gen"u*ous*ness, n. Macaulay.