When you're at a party and someone's throwing up in the bathroom, you grab the back of their head and stick it into the toilet!
Yo, I totally gave Seamus an Irish Baptism last night!
by Seamus McCoy March 14, 2013
1 more definition
When someone with an Irish background gets baptized,they impulsively go on a drinking binge right after.
Without his knowledge, an ordinary baptism turned out to be an Irish baptism for Jacob McGahuey.
by shumbert February 17, 2009