Most so called false alarms are really nuisance alarms.
A false alarm is when the alarm sounds and the initiating devices have not detected anything.
Pretty sure that “false alarm” & “nuisance alarm” are essentially synonyms of each other as they’re both untrue & annoying.
In the majority of cases when the fire alarm goes off and there is no emergency, the initiating devices were working correctly. One of the initiating devices did detect something. Hence the term nuisance alarm.
A true false alarm (yes, this sounds like an oxymoron) occurs when the fire alarm sounds and none of the initiating devices have detected anything.
In either case the system is crying wolf: it doesn’t really matter how, just that it does.