Kenneth G. Wilson (1923–). The Columbia Guide to Standard American English. 1993.
unstructured (adj.)
means “informally organized, free, lacking a structure.” It can be either pejorative or elevated: an unstructured course may be either stimulatingly free or maddeningly disorganized. The word is much used currently in its elevated sense. In tailoring, an unstructured jacket is a loose-fitting one that lacks interfacing and other internal support.
