What is Timeline?
1.
to timeline: To inform someone that what they just referenced/presented/discovered and showed others as something new and awesome is in fact older than crap. Origin from a "timeline" image on a message board that was to be posted at the time of timelining.
Over time, however, the process of timelining an individual is thought of as rude, due to the fact that the timelined individual has just been sassed out for no reason they are aware of.
"Hey, guys, look at this flash thing I just found! Hahaha, kamikaze watermelon-"
"TIMELINED!"
