I don't quite understand something:
source
Brazil will, in one form or another, be ready for the World Cup. But when it comes to hosting the tournament, those famous Brazilian smiles may already be slipping.
What does "slip" mean in this context? I cannot find a good definition in dictionaries.
Best Answer
It's a common idiom: a smile can slip from someone's face, meaning that they are no longer as happy about something as they used to be, or that their smile was false.