Polysyllabic
/ˌpɑːlisɪˈlæbɪk/
Definition 1 of 1
Pro Tip 1/3Syllable Stress
Pay attention to stress patterns in polysyllabic words which affect pronunciation and meaning. 
In 'polysyllabic,' the stress is on the third syllable: po-ly-SYL-labic.
Pro Tip 2/3Accent Variation
Different accents may influence how polysyllabic words are pronounced, so listen to varied sources. 
Americans might pronounce 'polysyllabic' slightly differently than Britons.
Pro Tip 3/3Reading Fluency
Practicing polysyllabic words can improve reading fluency and comprehension in English. 
She practiced reading polysyllabic words to become more fluent.