MOAR is a popular misspelling of the word "more," used online as slang in chanspeak to request a source for more of the posted content or similar content. The term was largely popularized by 4chan over the course of the 2000s, declining in popularity starting by 2013.
The origin of "MOAR" is unknown. It is most commonly used in image macros alongside pictures of various figures shouting or roaring to show urgency and is typically used to demand more of the content (usually pornographic) posted by the OP or a source for said content.
The term goes back to at least 2005, as evidenced by a YTMND site titled "NEEDS MOAR ZEPPELIN!!!!!" created on November 5th, 2005, featuring an image of a baby in a Led Zeppelin onesie screaming, garnering over 3,400 views in 16 years. On March 17th, 2006, Urban Dictionary user grrr_argh defined "MOAR" as "A combination of 'more' and 'roar,'" which may explain why it is spelled in all caps and used alongside images of shouting people or roaring animals.
According to Encyclopedia Dramatica, the term began on 4chan's /b/ (random) board. This is unconfirmed, but possible, as the term was largely used by the board in the early to late 2000s. Some early examples of the word in image macros appear in 2008, including a BlogSpot blog titled "moarmoar" that began in March 2008, and a number of image macros featuring the word on WikiMedia and Nasty Hobbit (shown below, left and right).
The word became extremely popular on 4chan and other imageboards over the course of the 2000s, often used to request more similar pornographic (but not always) material from the poster.
Lurk Moar is a phrase used primarily on imageboards and forums starting around 2006 to tell other users they need to post less and study the community before posting again. The phrase is frequently used as a derogatory euphemism to inform users they are not wanted or welcomed, but may also be intended as legitimate advice for new users (examples shown below, left and right).
Moar Krabs refers to a viral image and video of Mr. Krabs drawn grotesquely, saying "more" from a 2001 episode of SpongeBob Squarepants (shown below, left). The original upload was posted in 2008 but has since been removed, with one of the earliest reuploads dated December 4th, 2008 (shown below, right).
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