unlesse

Conjunction

unless

1. Except on a specified condition; if not.
   • I’m leaving unless I get a pay rise.
2. If not; used with counterfactual conditionals.
   • Who would know of Alexander or Caesar, or would respect the Stoics or the Peripatetics, unless they had been distinguished by the memorials of writers?1159, John of Salisbury, Policraticus, edited by Cary J. Nederman, Cambridge University Press, 1990, page 3 (Google Books view)
3. Except if; used with hypothetical conditionals.
   • Q. If Lieutenant P. had given the word "Fire," would you have fired, and at what?—A. I should not have known, unless he had told me what to fire at.1809, The Naval Chronicle for 1809: Containing a General and Biographical History of the Royal Navy of the United Kingdom with a Variety of Original Papers on Nautical Subjects. Vol. XXII. (from July...