What is referred to by 'a smoldering coal'?

Based on the clue 'a smart glowworm grows up to be one of these flies', what is the answer? What is referred to by 'a smelt'? What is referred to by 'a smelter for example'? Based on the clue 'a smoked sausage bake sail', what is the answer? Based on the clue 'a smoldering remnant in a dying fire', what is the answer? Based on the clue 'a smooth heavy cardboard is called this board afte...', what is the answer? Based on the clue 'a snack a sailor boy his dog bingo', what is the answer? What is referred to by 'a snail in strasbourg'?