אש is generally translated as "fire." However, consider Vayikra 1:7:
וְנָתְנוּ בְּנֵי אַהֲרֹן הַכֹּהֵן אֵשׁ עַל הַמִּזְבֵּחַ וְעָרְכוּ עֵצִים עַל הָאֵשׁ
The sons of Aharon the Kohen shall put "אש" onto the altar, and they shall arrange wood on top of the "אש"
"Fire" doesn't seem to make sense in this context - the wood would come before the fire. Can אש have a broader meaning which is not just "fire"?
I realize that Rashi's comment here does seem to imply that it refers to fire. I'm not sure what the fire is being caught on to. According to Rashi, is there something else not mentioned in the verse that is already on the altar to which the fire is catching?