The word "sacropromontory" is spelled with the prefix "sacro-" meaning "relating to the sacrum" and "promontory" meaning a high ridge of land. The pronunciation using IPA phonetics is /seɪkroʊprəˈmɒntəri/. The syllables are divided as "sa-cro-pro-mon-to-ry". The stress is on the third syllable "-pro-" and the last syllable "-ry". The spelling may appear difficult to pronounce, but breaking down the word into its syllables and understanding the meanings of the prefixes and suffixes can help in pronunciation.
The promontory of the sacrum.
A practical medical dictionary. By Stedman, Thomas Lathrop. Published 1920.