Longman Dictionary of Contemporary English
Douglas Harper's Etymology Dictionary
1775, from un- (1) "not" + obtainable (adj.). Related: Unobtainability.\n
Wiktionary
a. Not able to be obtained, acquired or reached.
WordNet
adj. not capable of being obtained; "a rare work, today almost inaccessible"; "timber is virtually unobtainable in the islands"; "untouchable resources buried deep within the earth" [syn: inaccessible, unprocurable, untouchable]
Usage examples of "unobtainable".
Dame so after luncheon they set off on foot, a fiacre being virtually unobtainable.
Steel and Nina Malapert made their way into the Rookery, disguised under heavy cloaks and holo faces, with just enough hints about them to suggest they were two well-off ladies, slumming it in the Rookery for pleasures unobtainable in the more civilized parts of the city.
Certain drugs are unobtainable, but the British have lost none of their old enthusiasm for medicine-taking, and the consumption of aspirin, phenacetin, etc.
The list of offerings was incredible: baked salmon steak, Maine lobster, roast sirloin, filet of sole, a whole roster of unobtainables, none of your dreary latter-day soybean clevernesses and seaweed confections.
Hunting dinos was fine, especially if it gave him the chance to test a few otherwise unobtainable weapons.
When unobtainable, a solution of 8 drachms of crystallized citric acid in 16 OZ.
But the last page of Rolland's report made plain that the scores of double agents Rolland had been able to infiltrate into even the highest ranks of the OAS had been outflanked by the anonymity of the, assassin, except to three men who were unobtainable in a hotel in Rome, and he could see for himself that the enormous archives of dossiers on everyone who had ever been remotely connected with the OAS, on which the Interior Ministry could usually rely for the information, had been rendered useless by one simple fact.
Only except they were, so everyone said, the jettest black of all social sets, the crème de la crème, the egg in the basket, the two unobtainable birds in the bush.