Question

What is the full form of Am. and Pm

Answer 1

 AM: Anti Meridiem,
PM: Post Meridiem 

Answer 2

$hi..$

AM and PM both are Latin words, used in 12-hour clock system to represent Before Noon and After Noon. They are also represented as A.M. and P.M. AM expand as Anti Meridiem which means "before midday" and PM expand as Post Meridiem which means "after midday"

$hope \: this \: helps...$