The spelling of the phrase "most lastgasp" may seem challenging, but it follows the English phonetic system. The word "last" is pronounced with a long "a" sound, so the "a" is doubled in "lastgasp" to indicate the same sound. The "g" is added to help differentiate the word from "lastasp". The stress is on the second syllable, indicated by the bold "gas" in the spelling. Therefore, the correct way to spell this phrase is "most lastgasp" /məʊst ˈlɑːstɡæsp/.