Irregardless is a word sometimes used in place of regardless or irrespective, which has caused controversy since the early twentieth century, though the word appeared in print as early as 1795. Most dictionaries list it as non-standard or incorrect usage, and recommend that "regardless" should be used instead.
Having no regard; heedless; careless.
Without attention to warnings or indications of bad consequences.
"Tatiana knew the yogurt had passed its expiry date, but she ate it regardless."
Paying no attention to; regardless of.
"Tatiana ate the cauliflower regardless of its colour.attention|en|usex doesn`t illustrate sense"
Irrespective, regardless. from mid 19th c.
Having no regard; heedless; careless; as, regardless of life, consequences, dignity.
Not regarded; slighted.
(usually followed by `of') without due thought or consideration;
"careless of the consequences"
"the proverbial grasshopper--thoughtless of tomorrow"
"crushing the blooms with regardless tread"
in spite of everything; without regard to drawbacks;
"he carried on regardless of the difficulties"
regardless; a combination of irrespective and regardless sometimes used humorously