DISINGENUOUS
disingenuous, artful
(adjective) not straightforward or candid; giving a false appearance of frankness; “an ambitious, disingenuous, philistine, and hypocritical operator, who...exemplified...the most disagreeable traits of his time”- David Cannadine; “a disingenuous excuse”
Source: WordNet® 3.1
Etymology
Adjective
disingenuous (comparative more disingenuous, superlative most disingenuous)
Not honourable; unworthy of honour
Not ingenuous; not frank or open
Synonym: uncandid
Assuming a pose of naïveté to make a point or for deception.
Usage notes
• Nouns to which "disingenuous" is often applied: attempt, argument, statement, conduct, people, excuse, question, assertion.
Source: Wiktionary
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.
Source: Webster’s Unabridged Dictionary 1913 Edition