regardless

Regardless is rather simply derived from the noun regard (meaning "attention" or "concern") plus -less - nothing too shocking about that. But poor regardless became embroiled in a usage scandal through no fault of its own when people began using irregardless as its synonym (probably blending irrespective and regardless). Irregardless originated in dialectal American speech in the early 20th century, and usage commentators have been decrying it since the 1920s, often declaring "there is no such word." Irregardless does exist, of course, but it tends to be used primarily in speech and it is still considered nonstandard. Regardless is greatly preferred.