Boyd’s Bible Dictionary:
(coop, tub). A drinking vessel of various designs, made of horn, clay, or metal (Gen. 44:2; 1 Sam. 16:13; 1 Kings 7:26). Used figuratively (Psa. 23:5; Isa. 51:17; Rev. 14:10; Matt. 20:22; 26:39).
Concise Bible Dictionary:
Various Hebrew words are so translated, having regard to the different uses to which the cup was put. It is frequently used for that which the cup contains, causing either joy or sorrow, as “I will take the cup of salvation and call upon the name of the Lord” (Psa. 116:13). “In the hand of the Lord there is a cup, and the wine is red....the dregs thereof, all the wicked of the earth shall wring them out and drink them” (Psa. 75:8; compare Rev. 14:10; Rev. 16:19). And so in many other instances; and especially in that of the cup of which the Lord Jesus drank when bearing sin (Matt. 26:27,39,42; John 18:11). In the Lord’s Supper the “cup” is put for the wine which was an emblem of the blood of Christ (1 Cor. 10:16,21; 1 Cor. 11:25-28).