The spelling of the word "steaminesses" is complex due to the combination of various elements. The root word "steam" has the IPA phonetic transcription of /stiːm/, with a long "i" sound and an "m" at the end. The suffix "-iness" adds the meaning of having the quality of steaminess, and its IPA phonetic transcription is /ɪnəs/. Finally, the plural suffix "-es" is added to make the word plural, and its IPA phonetic transcription is /ɪz/. Thus, the complete pronunciation of "steaminesses" is /stiːmɪnəsɪz/.
The word "steaminesses" appears to be a derivative of the word "steamy" with the addition of the suffix "-nesses".
The word "steamy" dates back to the mid-19th century and is primarily associated with the idea of producing or giving off steam, as in the context of steam engines and heated liquids. It also obtained a metaphorical meaning of being sexually suggestive or seductive, particularly in regards to writing or films with explicit content. It is likely that "steaminesses" was formed by adding the plural suffix "-es" to "steamy" and then adding the suffix "-ness" to indicate the quality or state of being steamy or sexually suggestive.
However, it's worth noting that "steaminesses" is not a commonly used word in modern English, and you might find variants like "steams" or "steaminess" to be more widely recognized and used.