irregardless

Etymology
Probably a ;  the word can also be analysed as  because it is possible that the prefix ir- was added to amplify the negative in regardless just as plain negatives often did at the time the word came into use (and still do in dialects).

Adjective

 * 1)  Irrespective, regardless.

Usage notes
Although well attested, this word is widely regarded as nonstandard and incorrect. Its use is proscribed by many speakers, who consider it inappropriate in any formal setting.