v.aux. (usu. foll. by to + infin.; present and past indicated by the following infin.) 1 expressing duty or rightness (we ought to love our neighbours).
2 expressing shortcoming (it ought to have been done long ago).
3 expressing advisability or prudence (you ought to go for your own good).
4 expressing esp. strong probability (he ought to be there by now).
Phrases and idioms:
ought not the negative form of ought (he ought not to have stolen it).
Etymology: OE ahte, past of agan OWE
2.
n. (also aught) colloq. a figure denoting nothing; nought.
Etymology: perh. f. an ought for a NOUGHT; cf. ADDER
3.
var. of AUGHT(1).
Useful english dictionary. 2012.