Answer:
This would depend on the intensity or the size of a fire.
Step-by-step explanation:
For instance, a small fire could be described as: kindled, flickering, dancing (in the case of a candle flame), smoldering, or crackling.
A medium size fire, such as a camp fire or a fireplace could be described as: crackling, blazing, burning, or roaring.
While a large or very intense fire (such as a forest fire or a house fire) could be described as: roaring, blazing, burning out of control, consuming, raging, or destroying.
If you were more looking for synonyms of ‘fire’, here are a few of my favorites: flame, blaze, incinerate, immolation, and inferno. (Edited to add a few I remembered: pyre, conflagration, and scorching.)