noun

a male child or youth.

a four-year-old boy

male child,youngster,youth,lad,young man,young fellow,young person,teenager,adolescent,juvenile,minor,junior,student,schoolboy,son,stripling,fledgling,whippersnapper,bairn,wean,laddie,pickney,kid,kiddie,tot,shaver,nipper,young ‘un,brat,urchin

exclamation

used to express strong feelings, especially of excitement or admiration.

oh boy, that’s wonderful!