acrimony agrimony alimony antimony ceremony harmony matrimony parsimony patrimony sanctimony testimony
The list above contains words which end in the sequence <mony>, which is pronounced məni. All of these words, where possible, have the main stress two syllables before the ending. The word hegemony can also have this stress pattern, but there is an alternative pronunciation with the main stress on the syllable immediately before the ending.
Here are some words which end in <ony>, but where the preceding consonant is not <m>:
cacophony chalcedony homophony monotony polyphony stereophony telephony
All these words have stress on the syllable before the ending, which is pronounced əni.