This word from the Greek referred originally to the ease and comfort felt by people who enjoy good health. The Greek elements are eu (well) and pherein (to bear/carry). Etymologically, euphoria is a feeling of well-being.
The earliest use of euphoria in English (1684) is as a medical term. The right medicine could produce a feeling of euphoria in a sick person (i.e., make a sick person feel well).
The adjective, introduced in 1888, is euphoric:
euphoric: characterized by a feeling of well-being, cheerful; also, producing or causing cheerfulness.
In modern usage, euphoria refers to a heightened feeling of well-being, such as the phenomenon referred to as “runner’s high”:
runner’s high (noun): a feeling of well-being or euphoria resulting from physical exercise, especially running.
M-W Online defines euphoria as: “a feeling of well-being or elation; especially one that is groundless, disproportionate to its cause, or inappropriate to one’s life situation.”
Here are some examples of usage from the Web:
The few truly euphoric moments I’ve experienced as a Steelers fan
The [prayer-induced] experience lasted probably only a second or two, but after it left my body I was left with this euphoria. Almost feeling like I was floating.
At 2:49 p.m. on Monday, city native George Lobaton experienced the euphoria of crossing the finish line of the 26.2-mile Boston Marathon.
What is it like to finish a novel? The first time you do it, you feel utter euphoria, and you should.
For [Ebola] survivors, the euphoria of having beaten the disease is soon followed by the battle to live with the stigma.
[Volunteers helping the homeless] experience the euphoria that comes from doing something good for someone who can’t help you in return.
Euphoria doesn’t last. The verbs commonly used to indicate its passing or dissolution are dissipate, evaporate, wear off, die down, and fade:
Now that the euphoria has worn off the cold hard facts remain.
But now the euphoria has subsided and the market [has undergone] a painful correction.
But now the euphoria has faded — partly no doubt because Spain is settling down to normal democratic apathy
Now the euphoria has died down, it’s back to business as usual.
Unfortunately, that euphoria typically dissipates when companies realize that the cloud technology they’ve invested in isn’t as easy or reliable as they thought it would be.
But little remains of the euphoria from those winter days when the beginning of a new era seemed to be dawning in Ukraine. That euphoria, however, has evaporated.
Here are some other nouns to name feelings of happiness and well-being: