...Irregardless is a word that many mistakenly believe to be correct usage in formal style, when in fact it is used chiefly in nonstandard speech or casual writing...Irregardless is considered nonstandard because of the two negative elements ir- and -less. It was probably formed on the analogy of such words as irrespective, irrelevant, and irreparable. Those who use it, including on occasion educated speakers, may do so from a desire to add emphasis. Irregardless first appeared in the early 20th century and was perhaps popularized by its use in a comic radio program of the 1930s.