A dictionary of Confusable Phrases: More Than 10,000 Idioms and Collocations

white marriage • white wedding
white marriage —a marriage union without sexual relations:
Maybe I should have written that the union of Bill Paxon and
Susan Molinari was rumored to be a “white marriage.”
white wedding —
1
. used with reference to the white color of
the wedding dress symbolizing purity and innocence: Mine
was a white wedding too. In fact, my dress was very similar
to the one Erica wears on screen. 2. a marriage ceremony in
which the bride is still a virgin: I was 26 and my wife was 2
1
when we got married (and it was a “white wedding” in the
traditional meaning of the term.)
white negro • white nigger
white negro —
1
. a person with black ancestry who has a pale
or albino complexion: He was one of that peculiar class called
Albinos, or white negroes. 2. (U.S. dated sl., derog.) a white
who defends the rights or interests of Black people : Both
Clarksons were counted among the activists whom Pitt in a
rare jest called the “white Negroes.” 3. (in nonce-use): The
Jewish Defense organization became another white negro,
which changed its color according to the political situation.
white nigger —(U.S. dated sl.) 
1
. (derog.) a white person who
does menial labor: “Ole Miss Meanses’ white nigger,” as some
of them called her, in allusion to her slavish life. 2. a Black
person who defers to white people and regarded as betraying
his social loyalty: Dr. Marcus Foster, a black suggested that
the children be equipped with identity passes…. The unfor-
tunate Foster was widely accused of being a white nigger. 3.
= white negro 3: Hippies have openly proclaimed themselves
“white niggers” by which they seem to mean that, like blacks,
they represent an alternative to the life style of majority-group
American culture.