bap·tize 
(băp-tīz, băptīz′)
(băp-tīz, băptīz′)v. bap·tized, bap·tiz·ing, bap·tiz·es
v.tr.
1. To admit into Christianity by means of baptism.
2.
a. To cleanse or purify.
b. To initiate.
3. To give a Christian name to a person; christen.
v.intr.
To administer baptism.
[Middle English baptizen, from Old French baptiser, from Late Latin baptīzāre, from Greek baptizein, from baptein, to dip.]
bap·tizer n.