The pronunciation of 'overwhelm' is given by the phonetic notation \ˌō-vər-ˈhwelm, -ˈwelm\ in a dictionary, indicating the initial unstressed syllable and the primary stress on the second part of the word, with options for the 'h' sound.
The pronunciation of the word overwhelm is indicated in a dictionary entry by the phonetic spelling provided between the backslashes. In this case, \ˌō-vər-ˈhwelm, -ˈwelm\ provides guidance on how to say the word.
The symbols represent different sounds that correspond to the American English phonetic alphabet. The word starts with an unstressed syllable "ō-vər" marked with a secondary stress (represented by ˌ) followed by a hyphen to indicate that the next part should be emphasized with primary stress, such as "hwelm" or "welm".
These notations help to understand how to say the word correctly and in this case, provide two pronunciation options, one with the 'h' sound and one without.