Cy Pres

These are old French words, which signify 'as near as.'

In cases where a perpetuity is attempted in a will, the courts do not, if they can avoid it, construe the devise to be utterly void, but expound the will in such a manner as to carry the testator's intentions into effect, as far as the rules respecting perpetuities will allow; this is called construction cy pres. When the perpetuity is attempted in a deed, all the limitations are totally void.
   

This entry contains material from Bouvier's Legal Dictionary, a work published in the 1850's.

As near as may be': a technical word used in the law of trusts or of wills to refer to a power that the courts have to, rather than void the document, to literal construction would give the document illegal, impracticable or impossible effect. - (read more on Cy-pres)