This hotel or pub is hi-fi ? Is that a correct sentence ? What are other good words one can use for a good quality pubs/clubs ?
"Hi-fi" is a real word, in the sense that it has been used and recorded in dictionaries for many years. But it means a "high-quality record player" (or cd player etc). Typically one with a separate amplifier and speakers. It is short for "high fidelity".
So you can't talk about a "hi-fi hotel" (unless you mean a hotel whose rooms are equipped with record players)
You have already answered your own question: You can say "Good quality hotel". Or you could use any of the hundreds of other adjectives with positive meanings: "A great/comfortable/luxury/friendly/superior hotel"
There is also the star systems for grading hotel facilties. A luxury hotel could be a "five star hotel", and this is used both strictly (To mean the hotel has been graded by an independent travel organisation) and informally to mean "luxury".
This question seems to be about slang, which is highly dependent on location and demographics. "Hi-fi" sounds ridiculous to me in this context, but I get what's intended and I imagine somebody somewhere probably does say this.
There are dozens if not hundreds of more "correct" (non-slang) choices like "good, great, fantastic, fabulous, wonderful, classy." Many of these do have subtle connotations which also tend to vary from region to region. Without knowing more about the nuances you want to convey, and the location and audience to whom you want to convey them, it's impossible to suggest a single word.
I agree with the accepted answer, but since in my native language "hi-fi" can be colloquially used to mean either high quality or expensive and obsessed over insignificant details, I feel like proposing another answer.
"High-end" has similar connotations when talking about audio equipment, but can be used to describe any product or service.
Other answers have explained why it is not correct to describe a hotel or pub as "hi-fi," but none have suggested the adjective that I hear most often in casual speech (American English, Southwestern region):
"Is this a nice hotel/pub?" or "Is this hotel/pub nice?"
Definition 2 at Merriam-Webster Learner's Dictionary:
attractive or of good quality
- nice restaurants
- a nice car/house