Antonyms for the phrase "fanning fire" include "smothering flames," "extinguishing blaze," and "dampening embers." These words represent actions that have a negative effect on a fire, quenching its flames and slowing its growth. They are often used in the context of fire safety, as smothering flames or extinguishing a blaze can help prevent the spread of fire and save lives. However, in other situations where fire is desired, such as in camping or cooking, these actions are not desirable. In these situations, words like "adding fuel," "stoking flames," or "igniting kindling" may be used to describe actions that will help the fire grow and thrive.