Ambiguity
The Fallacy
Using words that can mean two different things to trick someone.
Why it's wrong
It's like playing a word game to trick people. You say something that sounds like a promise, but later you say you meant something else.
Example
I told mom I wouldn't eat the cake on the table. So I picked it up and ate it on the couch instead.
What the Fallacy?! (ELI5 Edition)