A word meant to replace fuck
in an specifically explanitory manner. To exclaim "fook!" is the equivilent of exclaiming its well known root.
The earliest known usage of fook in its modern form is generally credited to "KMan" in an IRC conversation in which he repeatedly wrote fook every time he lost a round in Half Life. The final count was 96. (2001)
Contrary to intellectual assumptions, the term fook has no foriegn origin and was spelt as it was meant to be stated.
Invalid usage (in terms of definition) of fook may be in the general form:
"I fooked her good. Real Good."