Wiktionary
fizzle out
vb. To lose excitement, to become less exciting.
WordNet
Usage examples of "fizzle out".
I thought about going back to Nebuchadnezzar, looking for a target, but the War Mother and I agreed, I'd just fizzle out and give the planet another useless scar.
I mean, its been such a long time since we held a meeting, and societies just fizzle out if theyre not kept going somehow.
That way we can stall making a report for a week or so, and let the matter fizzle out.
All of them, without exception, would fizzle out in the waters of San Francisco Bay.