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 desireto add emphasis. irregardless first appeared in the early 20th century and was perhaps popularized by its use ina comic radio program of the 1930s
Word origin
[1910–15; ir-2 (prob. after irrespective) + regardless]This word is first recorded in the period 1910–15. Other words that entered Englishat around the same time include: functionalism, homeroom, isotope, radio, spotlight