The Collaborative International Dictionary of English v.0.48:
Vanishing \Van"ish*ing\,
a. & n. from Vanish, v.
[1913 Webster]
Vanishing fraction (Math.), a fraction which reduces to the
form 0/0 for a particular value of the variable which
enters it, usually in consequence of the existence of a
common factor in both terms of the fraction, which factor
becomes 0 for this particular value of the variable.
--Math. Dict.
Vanishing line (Persp.), the intersection of the parallel
of any original plane and the picture; one of the lines
converging to the vanishing point.
Vanishing point (Persp.), the point to which all parallel
lines in the same plane tend in the representation.
--Gwilt.
Vanishing stress (Phon.), stress of voice upon the closing
portion of a syllable. --Rush.
[1913 Webster]