1. Changing the size of all the periods in an essay to make it appear longer than it actually is. Commonly used to meet length requirements of a paper.
2. The reasoning a girl uses to avoid having sexual intercourse.
1. Oh shit! my essay is short by about a page. Time to use the period trick!
Mary: So I saw you and Brad together last night! Did you...ya know?
Sammy: No, I really didnt want to have sex with him, so I pulled the period trick and just gave him a bj.
The process of doing a "Find -> Replace" in Microsoft Word, in which you replace all periods in the paper with a larger size period. This can add one or more pages to the length of a long paper.
I used the Period Trick to make all my periods 14 font and got the extra page I needed to finish my essay!
Best friend to college kids everywhere.