Noun
wedge - A piece of material with a thick end that tapers to a thin edge, used to split, support, or secure things; also something that forces separation or division between people or groups.

The disagreement drove a wedge between the two longtime friends, and they really didn't enjoy spending time together anymore.
shortcut - A simplified way to complete a task, often by bypassing steps in a process; or a path or way that reduces the usual time or distance required to reach a destination.

He surprised the teacher by figuring out a shortcut method of solving the math problem that saved time compared to the method she had taught before.
fairytale - A children's story about magical and imaginary beings and lands; or something that is too good to be true or seems unreal.

He told a fairytale about how he got the job, but no one believed him, and people suspected that he had a relative in management.