This is the 10544th most frequent Portuguese word.
flácido
Flácido: limp, flabby, or lacking firmness.
Here, 'flácido' describes the state of the balloon when it is sagging and lacks firmness due to loss of air.
O balão estava flácido após perder o ar.
The balloon was flaccid after losing air.
In this case, 'flácido' refers to the sagging and reduced tightness of the skin, often due to aging or lack of elasticity.
A pele do idoso tornou-se flácida com o passar dos anos.
The elderly person's skin became flaccid with the passing years.
Here, 'flácido' metaphorically describes the quality of the argument as weak, ineffective, and lacking substance.