1) to dip repeatedly, to immerse, to submerge (of vessels sunk)
 2) to cleanse by dipping or submerging, to wash, to make clean
    with water, to wash one's self, bathe
 3) to overwhelm

 ++++
   Not to be confused with G0911, bapto. The clearest example that shows
 the meaning of baptizo is a text from the Greek poet and physician
 Nicander, who lived about 200 B.C. It is a recipe for making pickles
 and is helpful because it uses both words. Nicander says that in
 order to make a pickle, the vegetable should first be 'dipped'
 (bapto) into boiling water and then 'baptised' (baptizo) in the
 vinegar solution. Both verbs concern the immersing of vegetables in a
 solution. But the first is temporary. The second, the act of
 baptising the vegetable, produces a permanent change.
   When used in the New Testament, this word more often refers to our
 union and identification with Christ than to our water baptism. e.g.
 Mark 16:16. 'He that believes and is baptised shall be saved'.
 Christ is saying that mere intellectual assent is not enough. There
 must be a union with him, a real change, like the vegetable to the
 pickle!
   Bible Study Magazine, James Montgomery Boice, May 1989.