The word "duncest" appears to be misspelled. The correct spelling of this word should be "densest", which is pronounced /ˈdɛnsɪst/ in IPA phonetic transcription. The ‘d’ sound is pronounced as /d/, followed by the vowel ‘e’ sound pronounced as /ɛ/. The ‘n’ sound is pronounced as /n/ and followed by the ‘s’ sound pronounced as /s/. Finally, the ‘t’ sound is pronounced as /t/. The word "densest" means the most tightly packed or closely crowded together.