Firm and Enterprise

Firm

Firm is the word used to describe a business partnership when you want to make that partnership sound very serious. As an adjective, firm can be used to describe something that is secure or steadfast.
After graduating from law school, l decided to take a job in a law firm specializing in civil litigation. The best in the area was the well established Smith and Mitch.
When on a job interview, it is always a good idea to shake the hand of the person interviewing you. It is important to remember to make your handshake firm, to show you have strength of character.
An idiom that uses firm as an adjective is firm believer, which means a person whose belief is solid and unchanging. Firm is also a verb, and there is an expression which uses it that way: firm up, which means to make uncertain plans more certain.
My third grade teacher, Mrs. Bassman, was a firm believer in the idea that "less is more." She did very little herself, and expected more from us all the time!
Peter and I had made loose plans to get together with our families over the weekend. On Thursday evening, I called him to firm things up and thrash out the details.

Enterprise

An enterprise is a company, business, or other type of organization with a purpose. It can also refer to any undertaking or endeavor.
After high school, Danny chose not to go to college. Instead, he began working as an apprentice to a plumber. Now, he is the owner of a small plumbing enterprise with four full¬time employees.
There could be no doubt about it—the dog had taken George's glasses and run off with them. Figuring that out was the easy part, but getting them back again would prove to be a far more difficult enterprise.
Enterprise can also be used to mean the willingness to take on a specifically difficult or daunting task. From this, the adjective enterprising is derived, meaning having the quality of enterprise.
Mr. Verdecchio praised Tom for all he'd done to help bring the project to its fruition, and said that he'd shown great enterprise and initiative. Tom felt sure he'd get a promotion soon!
Mrs. Phillips smiled at me and told me that she was sure I'd think of a way to find the money to attend university in the autumn. She said I was a very enterprising young woman, and that the world was full of opportunities for such women.