Answer:
Transient means something which is temporary or short-lived. Here, when the author says terribly transient feet, she refers to the ever changing imprints of the feet left on the sea sand. The sea never appears to change but the human life is transient.
Step-by-step explanation:
terribly transient feet - In this phrase, the word feet is used to describe the human beings. ... This phrase means that human life is not permanent but temporary. The human beings have to die one or the other day but the sea is permanent . It is still going to be their after our death