Can you help me understand this word?

Frank Rich in the Sunday NY Times on 10/28/07 wrote this sentence: “You have absolutely nothing to fear from me,” Rudy [Giuliani]disingenuously told the assembled at the Values Voter Summit last weekend.

I understand the definition from American Heritage Dictionary: 1. Not straightforward or candid; insincere or calculating: “an ambitious, disingenuous, philistine, and hypocritical operator, who … exemplified … the most disagreeable traits of his time” (David Cannadine).

Wouldn't the root "genuous" mean true, so in-genuous mean not-true (for example, in-sincere). So would dis-in-genuous mean not-not-true, a double negative? Just wondering.

there is no English form genuous, OED gives the derivation as from L. ingenu-us native, inborn, free-born, having the qualities of a freeman, noble, frank (f. in- (IN²) + gen-, stem of gignere to beget) + -OUS.

this use of the prefix in- was probably meant as an intensive - in any case, it's not a negation.

so, disingenuous is 'not ingenuous'.

note: occasionally the prefix dis- also acts as intensive (but not here, according to the AHD usage mavens).

thanks

this use of the prefix in- was probably meant as an intensive - in any case, it's not a negation

Yes. Another use of in- as an intensive prefix is in inflammable and possibly in irregardless.

Mm--as in, we would say 'he was inflamed by that remark', but never 'he was flamed...'.
We had a thread, or at least a couple of posts, one time, about flammable and inflammable. (Was going to put vs., but.)

Disingenuous usually gives me the impression of pretended sincerity and innocence of mind. But that may be becouse I mix it up with ingenue.