The drink offering (Hebrew nesek) was a form of libation forming one of the sacrifices and offerings of the Law of Moses.
The Hebrew noun nesekh is formed from the Qal form of the verb nasakh, "to pour," hence "thing poured." The verb and the noun frequently come together, such as nasakh [aleha] nesekh, literally "pour [on it] a poured thing" as in the only pre-Exodus use, that of Jacob's libation at a pillar in Genesis 35:14. The etymology "poured thing" explains the existence of the rarer secondary use of the verb nasakh for "cast" (an idol), and the noun nesekh for a "thing poured" (also an idol).
The drink offering accompanied various sacrifices and offerings on various feast days. Usually the offering was of wine, but in one instance also of "strong drink" (Numbers 28:7). This "strong drink" (Hebrew shaikhar שֵׁכָר, Septuagint sikera σίκερα as Luke 1:15, but also methusma in Judges 13:4 and Micah 2:11) is not identified.
In Akkadian texts, and Ugaritic epics there are references to libations, and sometimes the same verb stem N-S-K "to pour" is used. Psalm 16:4 gives reference to a "drink offering" of blood among pagans, but generally in ANE religions libations were also of wine.
In the Talmud the view of Rabbi Meir was that the blood of the sacrifices permits the drink offering to the altar (B. Zeb. 44a).