1. (literal) burn without flame
1. He sat by the fire for a long time, watching the ashes smolder.
2. (figurative) to quietly burn with suppressed anger; to simmer with controlled anger
2. When policemen and bureaucrats abuse us, all we can do is smolder with helpless rage.
Smolder, remove the 'm' from the word, it becomes solder. For soldering, we do not require fire, it is done by electricity or by burning copper zinc, lead etc. smol + der -- 'smol'. small 'der'. fear (in hindi). in handling small things the fear is they might break down.