The spelling of the word "more inundatory" can be confusing due to its pronunciation. It is pronounced as /mɔːr ɪnˈʌndeɪtərɪ/ where "inundatory" means "causing or bringing flooding". The word "more" acts as an intensifier here. In terms of spelling, it follows the general pattern of adding "-atory" to the noun form of the verb. While it may take some practice to get used to spelling and pronouncing this word correctly, it is an important one to know in discussions about flooding and disaster relief.
The term more inundatory is not a common or established English word. As such, there is no clear etymology or history associated with it. It appears to be a combination of the adjective more and the noun inundatory. However, inundatory itself is not a commonly used word either. It is likely a neologism or a technical term specific to a certain field or context. Without further information or context, it is challenging to provide a precise understanding of the etymology or meaning of more inundatory.