adjective/vɔl.ka.nik/
volcanic
“Nous verrons bien. C'est le mot du professeur, qui, après avoir baptisé cet îlot volcanique du nom de son neveu, donne le signal de rembarquement.” — "That is what we shall see." So says the Professor, who, having named this volcanic islet after his nephew, gives the signal to embark again.
Related: colonne volcanique, panache volcanique
From volcan + -ique.