The Random House American Dictionary [antikvár]

Pronunciation Key The symbol ('), as in moth'er, is used to mark primary stress; the syllable preceding it is pronounced with greater prominence than the other syllables in the word. The symbol ('), as in grand'moth'er, is used to mark secondary stress; a syllable marked for secondary stress is pronounced with less prominence than the one marked (') but with more prominence than those bearing no stress mark at all.