Origin: Germanic Old English suffix
Ought has 6 different meanings across 1 category:
A statement of what ought to be the case as contrasted with what is the case.
"In old manuscripts, the digit often appears as an ough or ought to represent the number zero."
Alternative spelling of aught; cipher, zero, nought.
In plain English: An ought is something that people believe should be done because it is right or necessary, even if they don't have to do it.
"The whole point of this meeting is to figure out what our next move ought be."
Usage: Use "ought" as a noun only in formal or philosophical contexts when referring to an ideal state that contrasts with reality. Avoid using it casually for the number zero or as an adverb meaning "at all," which are spelled differently.
simple past tense of owe
"You ought to apologize to her for what you said yesterday."
Indicating duty or obligation.
In plain English: To ought is to feel that something should be done because it's right.
"You ought to call your mother tonight since it is her birthday."
Alternative spelling of aught; at all, to any degree.
"The question is not whether we ought try, but how hard we should attempt it."
In plain English: Ought is an old-fashioned way of saying should, meaning you are expected to do something because it is right.
"You ought to go home before it gets dark."
Alternative spelling of aught; anything
"In archaic poetry, you might find lines referring to the value or nature of ought as an alternative spelling for aught."
Ought comes from the Middle English word for "owned," which was originally the past tense of the Old English verb meaning "to possess." Over time, this sense of ownership shifted to mean what one is morally required to do or give.