In essence, a nicer term for someone who is a hypocrite, or is being hypocritical. Comes from 'double standards'.
I prefer the term "double standardised".
Mathematically speaking, the obnoxious idea that it's OK for 56 to insult 82, but it's NOT OK for 82 to insult 56. Of course, 56 and 82 can be replaced with many different races, religions, etc.
A man sleeps with numerous women: Considered OK
A women sleeps with many men: Considered NOT OK
A woman physically hurts a man because she feels abused: ACCEPTED
A man physically hurts a woman because he feels abused: NOT ACCEPTED
A white person is successful: Assumed to be because of HARD WORK
A black person is successful: Assumed to be because of AFFIRMATIVE ACTION
A black person does poorly on a standardized test: Assumed to be because of BIAS in the test
A white person does poorly on a standardized test: Assumed to be because of LAZINESS, LACK OF EFFORT, etc.
A Christian is a very strong believer and mentions his love of God: Viewed as HEALTHY and PASSIONATE
An Atheist is very strong in his belief of no God: Viewed as CRAZY, CONFUSED, MISLEAD, etc.
An Atheist views Christians as unaccepting as a group: Viewed as NORMAL and is ACCEPTED
A Christian views Atheists as unaccepting as a group: Viewed as being UNFAIR and DOGMATIC
...I could go on forever. Point is: DOWN WITH DOUBLE STANDARDS! People aren't that different, and double standards only enforce all kinds of discrimination! GRRRR...
According to certain actual, credible dictionaries (which I cannot name because of potential legal issues), irregardless evolved in the early 20th Century United States from the word "regardless". Frequently those who engage in hypercorrection (yes, that is a word, look it up) say that there is "no such word". However, this is misleading and ignores both the inevitable evolution of the English language as well as the authoritative comments of most English dictionaries, which do in fact recognize it as a valid colloquialism. (Most do so whilst still observing that most people do not consider it proper in "formal" English).more...
The argument that the word contains a double negative and and is therefore improper ignores countless other commonly used words which do the very same thing; e.g., "debone", "unravel". A similar argument could also be made for the seemingly nonsensical yet true proposition that "flammable" and "inflammable" mean the same thing.
It also fails to take into consideration that even standardized, "proper" English has very few firm rules, that most rules of proper English have many exceptions, and that formal vocabulary, grammar, spelling, etc. vary from place to place. (Colour/color; 'quotes'/"quotes"; "punctuation inside quotes,"/"punctuation outside quotes", possessive's apostrophe/its lack of apostrophe, while/whilst, and the like.)
Of course, this does not excuse the complete and utter abuse of English by many people today; e.g. "u" for "you"...