The spelling of the phrase "more subfuscous" can be explained using IPA phonetic transcription. The word "subfuscous" is pronounced as /səbˈfʌskəs/ which means dark or gloomy in colour. When the word is combined with "more", it creates a comparative form indicating a higher level of darkness or obscurity. The pronunciation of the phrase would be /mɔːr səbˈfʌskəs/. So, if you want to describe something as darker or more obscure than something else, you can use the phrase "more subfuscous".
The word "subfuscous" is derived from the Latin term "subfuscuus", which is a combination of the prefix "sub-", meaning "below" or "under", and the adjective "fuscus", meaning "dark" or "dusky". When these two elements are combined, "subfuscous" is formed, essentially meaning "somewhat dark" or "dusky".
The word "more" in the phrase "more subfuscous" serves as an intensifier, indicating an increased degree of darkness or dusky appearance. Therefore, when used together, "more subfuscous" indicates a greater level of darkness or duskiness.