The spelling of the word "sombrest" may seem confusing, but it is actually quite simple when broken down into its individual sounds. The IPA phonetic transcription of the word is /ˈsʌm.brɪst/. This indicates that the first syllable is pronounced "sum" with a short "u" sound, followed by the consonant blend "br" and the vowel sound "i" as in "bit." The final consonant blend "st" is then added. "Sombrest" is the superlative form of "sombre," meaning extremely serious or gloomy.
There doesn't seem to be a direct match for the word "sombrest" in English. It is possible that it is a misspelling or a rare variant of the word "somberest", which comes from the adjective "somber". The etymology of "somber" can be traced back to the Latin word "sombrosus", which means "shady" or "shadowy". It eventually evolved into "sombros" in Old French and then into "somber" in Middle English, referring to darkness, gloominess, or seriousness.