scorch, burn, scald, torch, bonfire
燋 centers on intense heat applied to something: scorching, burning, scalding, or using a torch or bonfire. The meanings all involve fire causing damage or providing strong heat.
燋 combines 火 (fire) with 焦 (scorch, char), reinforcing the idea of burning or scorching. The exact historical development is uncertain, but the component relationship is visually clear.
Fire 火 on the left and scorch 焦 on the right: a double dose of heat. Picture a bonfire so intense it scorches everything nearby.
For ショウ, imagine a show of flames: a torch-lit performance where fire scorches the stage. Show -> ショウ.