Before or preceding.
[Latin ante, before.]
The sense is either of something placed in front of another or existing earlier in time. The first idea is found in antechamber, anteroom, and anterior (situated towards the front of the body); an antepenultimate item is the last but two in a series. The second sense appears in antenatal (before birth), antedate (to pre-date), antebellum (before the war, especially the US Civil War), and ancestor (Latin cedere, to go, hence to go before or precede). Some that appear to be formed from the equivalent Greek prefix anti- actually contain ante-: anticipate, antique. Its opposite is post-.