This is Jaime BonneChance's correct take on " What is cheating"

Jaime BonneChance

If you read the WWF Rulebook, you will know that it is NOT possible to violate WWF rules in order to gain advantage over your opponent, which is the primary definition of cheating.
http://newtoy.zendesk.com/entries/95593-words-with-friends-rulebook

Scrabble, the board game, does have a rule against consulting a dictionary before you play your word. Some players assume this also violates WWF rules. It does not. However, you & your opponent are free to agree to any extra rules you wish before you start your game.

The overwhelming majority of players who post complaints about "cheating", if asked, define it as 'playing a word they don't know' aka 'weird words' or more absurd: 'playing a word they never use in "everyday conversations''. These are novices who clearly have little experience with any word game- crosswords, anagrams, Scrabble, WWF.
Others who post complaints have defined it as: using 2-letter words, using the built-in feature commonly known as plugging or plug&play (playing tiles even if you aren't sure they form an acceptable word), bricking/stacking (parallel placement), playing one bingo, playing two or more bingos in one game, bookending (adding tiles to beginning or end of existing word, playing high-scoring words, etc. all of which are valid acceptable plays. Many assume YOU are using outside help (descrambler apps/sites, dictionaries on line/paper, Uncle Joe, etc.) if you do any of the above because THEY can't do it without outside help. Most experienced players find using outside help more of a hindrance than a help.

Posters who request 'no cheats' when requesting games also rarely define it.
Advice: ask them what their rules are in a chat bubble before you play a word or you will soon join the very large club of WWFers accused falsely and, at times, violently.

 And I quite agree, Henry