IPA: //ʌnˈæksɛntɪd//
KK: /ʌnˈæksɛntɪd/
Describing a word, syllable, or letter that does not have a diacritical mark or is pronounced with little to no stress.
In the word 'banana', the second syllable is unaccented.
Unaccented → It is formed from "un-" (meaning not) and "accented" (from Latin "accentus", meaning a song or tone). The word "unaccented" means not having an accent or emphasis in pronunciation.
Think of 'not' ('un-') having a 'tone' or 'song' ('accentus') — that's why unaccented means lacking emphasis in pronunciation.