Definition of primary stress in US English:

primary stress

noun

Phonetics
  • The strongest accent in a word or breath group.

    Compare with secondary stress
    • ‘The secondary stress can precede or follow the primary stress, and there need not be an intervening syllable.’
    • ‘A secondary stress after the primary stress is an unreduced syllable in the tail of the tone group.’
    • ‘The unstressed syllables don't matter as long as the number of primary stresses remains constant from line to line.’
    • ‘To discover where primary stress goes in the words in this exercise, speak each word aloud and place special emphasis on the syllable that you think should be stressed.’

Pronunciation

primary stress

/ˌpraɪˌmɛri ˈstrɛs//ˌprīˌmerē ˈstres/