rankshift

(in systemic linguistics) to use a unit as a constituent of another unit of the same or lower rank on the rank scale, as in using the phrase next door within the phrase the boy next door or the clause that you met yesterday within the phrase the girl that you met yesterday.

the process of rankshifting.

a phenomenon in which a unit at one rank in the grammar has the function of a unit at a lower rank, as for example in the phrase the house on the corner, where the words on the corner shift down from the rank of group to the rank of word

to shift or be shifted from one linguistic rank to another