What does "enough" mean?

Additional senses

1. 2.Fully; quite; -- used to express slight augmentation of the positive degree, and sometimes equivalent to very; as, he is ready enough to embrace the offer. I know you well enough; you are Signior Antonio. Shak. Thou knowest well enough . . . that this is no time to lend money. Shak.
2. 3.In a tolerable degree; -- used to express mere acceptableness or acquiescence, and implying a degree or quantity rather less than is desired; as, the song was well enough. Note: Enough usually follows the word it modifies.
3. 4.A sufficiency; a quantity which satisfies desire, is adequate to the want, or is equal to the power or ability; as, he had enough to do take care of himself. "Enough is as good as a feast." And Esau said, I have enough, my brother. Gen. xxxiii.
4. 5.An exclamation denoting sufficiency, being a shortened form of it is enough.