bedim comes from the intensive prefix be- + dim. Dim is from Old English dimm ('dark, obscure'), from Proto-Germanic *dimbaz. Morphologically, the word is transparent as a compound: its parts remain visible in the modern spelling, while the older history of those parts supplies the deeper ancestry. In modern use, the verb sense is "to make dim or obscure", which keeps the etymology connected to the word's present dictionary value rather than treating it as a merely historical label. The wider word family includes related English forms such as dim and derivatives such as bedimmed, bedimming, showing how the same base continues to support neighboring English vocabulary. The principal historical forms in the chain include Old English be-, Old English dimm, which anchor the explanation in named linguistic material.