adj. & n.
predic.adj. (governing a noun like a preposition) 1 of a value equivalent to (is worth $50; is worth very little). 2 such as to justify or repay; deserving; bringing compensation for (worth doing; not worth the trouble). 3 possessing or having property amounting to (is worth a million pounds).
n. 1 what a person or thing is worth; the (usu. specified) merit of (of great worth; persons of worth). 2 the equivalent of money in a commodity (ten pounds' worth of petrol). for all one is worth colloq. with one's utmost efforts; without reserve. for what it is worth without a guarantee of its truth or value. worth it colloq. worth the time or effort spent. worth one's salt see SALT. worth while (or one's while) see WHILE.
[ OE w(e)orth ]