Dictionary entry

Should

Webster's Dictionary 1913

Should (?), imp. of Shall. [OE. sholde, shulde, scholde, schulde, AS. scolde, sceolde. See Shall.] Used as an auxiliary verb, to express a conditional or contingent act or state, or as a supposition of an actual fact; also, to express moral obligation (see Shall); e. g.: they should have come last week; if I should go; I should think you could go. “You have done that you should be sorry for.” Shak.

Syn. — See Ought.