This is the 11614th most frequent Spanish word.
fluir
To flow.
In this sentence, 'fluir' is used to describe the natural and literal flow of the river.
El río fluye serenamente hacia el mar.
The river flows serenely towards the sea.
Here, 'fluir' is used metaphorically to describe how the conversation progressed smoothly.
La conversación entre ellos fluía sin esfuerzo.
The conversation between them flowed effortlessly.
In this case, 'fluir' conveys a figurative sense, suggesting allowing situations to progress naturally without interference.