flat chat

chat up

To talk to (someone) in a friendly, open, or casual manner, sometimes also in a charming or affected manner, usually to curry favor, and sometimes flirtatiously with the intention of establishing a romantic or sexual encounter or relationship with that person.

F in the chat

condolences, regret, or sympathy.

flat on one's back

Without recourse; helpless.

flat out

At top speed.

flat strap

At maximum capability, intensity, or speed.

knock someone flat

To knock someone down; to hit someone so they fall to the floor.

L in the chat

A loss, failure, or unfortunate event.