1. to stop working or fail completely.

Her marriage fell apart after about ten years.

The deal to sell the company fell apart last summer.

2. to break into pieces.

Cook the tomatoes until they begin to fall apart.

When the roof wasn't repaired, the building really began to fall apart.

• not judge a book by its cover
• not know beans about
• not know beans about something
• not know from Adam
• not know if are coming or going
• not know if you are coming or going
• not know someone from Adam
• not know the first thing about
• not know the first thing about something
• not know the half of it
• not know the meaning of the word
• not know what hit
• not know what hit you
• not know where to put
• not know where to put yourself
• not know where to turn
• not know whether are coming or going
• not know whether to laugh or cry
• not know whether you are coming or going
• not know which way to turn
• not let the grass grow under feet
• not let the grass grow under your feet
• not lift a finger
• not long for this world
• not look a gift horse in the mouth