Grab the chance, take a risk, etc.
"Believe it."
Spontaneous
While quite a specific noun, idiom could have the synonyms phrase, expression, saying, dialect, or slang.
Beating around the bush would be the synonym.
At the moment
The synonym of moment is a brief moment of time
No, a synonym is a word that means the same as another word. An idiom is a phrase that does not have a literal meaning. Ex, mountains out of mole hills.
"Believe it."
Have a light bulb moment.
Spontaneous
While quite a specific noun, idiom could have the synonyms phrase, expression, saying, dialect, or slang.
Beating around the bush would be the synonym.
Time
The time being.
At the moment
Heliocentric is a synonym of geocentric.
celebration, moment, happening, event