"waiver of right to take against the will of the other" = "renuncia al derecho de optar por la porción sucesoria legal en lugar de la dispuesta en el testamento"

Here is the definition of "to take against the will" provided in Black'Law Dictionary (7th edition):

"A spouse's statutory right to choose, upon the other spouse's death, either the share under the deceased spouse's will or the share of the estate as defined in the probate statute, which usually amounts to what a spouse would have received had he died intestate."