1.  shortage(n = noun.attribute) deficit, shortfall - the property of being an amount by which something is less than expected or required; "new blood vessels bud out from the already dilated vascular bed to make up the nutritional deficit"
is a kind of deficiency, inadequacy, insufficiency
has particulars: oxygen deficit

2.  shortage(n = noun.state) dearth, famine - an acute insufficiency;
is a kind of deficiency, lack, want

   Amount or extent of deficiency, as determined by some requirement or standard; as, a shortage in money accounts. [1913 Webster]

shortage, n. (often foll. by of) a deficiency; an amount lacking (a shortage of 100 tons).

N  incompleteness, deficiency, short measure, shortcoming, insufficiency, imperfection, immaturity, half measures, defect, deficit, defalcation, omission, caret, shortage, interval, break, noncompletion, missing link, missing piece, missing part, gap, hole, lacuna, incomplete, imperfect, unfinished, uncompleted &c (complete), defective, deficient, wanting, lacking, failing, in default, in arrear, short of, hollow, meager, lame, halfand-half, perfunctory, sketchy, crude, mutilated, garbled, docked, lopped, truncated, in progress, in hand, going on, proceeding, incompletely, by halves, caetera desunt, caret.