PERTAINING TO CONCLUSIONS FOR OVER 160 YEARS: According to Random House, "conclusory" has been a word since approximately 1840-1850. State court judges in the United States began using the word in 1908. In re Canakos, 111 N.Y.S. 601, 601 (Sup. Ct. App. Term 1908). Federal judges began using it in 1942. Guth v. Groves, 44 F. Supp. 851, 853 (S.D.N.Y. 1942). Now judges use it all the time -- in 943 cases reported in 2012 alone (according to a Lexis search), or in over 78 cases per work day, excluding court holidays. Because judges use the word "conclusory" when they define or make law, lawyers also have to use the word, though they don't need much coaxing. Lawyers use "conclusory" like bakers use flour.
Microsoft Word is the dominant word processing software used by lawyers. Microsoft Word has had spell-check since at least 1995.
According to Lexis, there are more than 3000 reported decisions* in which Microsoft is a party and the word "conclusory" appears in the text of the decision.
So why does Microsoft spell-check still stubbornly refuse to accept "conclusory" as a word?