cracked up
Favorably described or presented; praised. Usually used in the expression not what it's cracked up to be.
The independent writer's life isn't always everything it's cracked up to be.
In bad weather, a sailing cruise isn't what it's cracked up to be.
crackpot
An eccentric person with ideas that don't make sense to most other people.
Don't believe what Uncle Noam tells you - he is a crackpot.
Eccentric; crazy (adjective).
That's a crackpot idea.
get cracking
To hurry up, to start moving fast. Used mostly as an imperative.
Come on, you guys, let's get cracking! (Let's hurry up!)
To begin to move; get started.
The foreman told the workmen to get cracking.
hard nut to crack
tough nut to crack
Something difficult to understand or to do.
Tom's algebra lesson was a hard nut to crack.
Mary found knitting a hard nut to crack.
take a crack at
To try doing something.
It was a difficult challenge to reorganize our antiquated campus, but the resident architect decided to take a crack at it.
wisecrack
A joke or witty remark usually made at someone else's expense.
The comedians kept up a steady stream of wisecracks.