An abbreviation of "Why, though?" mainly used as a joke or pointless comment in online discussions.

The phrase picked up a large following in popular random-topic communities on GreatestJournal.com.

A term used to reference cannabis/marijuana/weed.

"Y tho" is a term used regularly nowadays. Stemming off of the phrase "why, though" it has been recently used to show confusion in a trolling type of manner. If, say, someone does/says something unintelligent, it is appropriate to reply with "y tho". For people not to confuse "y tho" with "why, though", squint your eyes while protruding your neck and calmly, in a small voice say "y tho?".
(Also there is a meme associating with this phrase.)

Y tho is an other way of saying Why though. People use it mostly when they are texting

Used to express hopeless frustration when something goes wrong. Used mainly by people originating from Tumblr.

An abbreviation for "Why Though?". Often used amongst chat groups and teenagers. Often read in a whiny voice, or sarcastically.

A massive lacking of understanding or comprehension of what you are witnessing. To be confused beyond the realities of the real world. A true blown lightbulb moment.