IPA: /ˈfrækʃənəli/
KK: /ˈfrækʃənəli/
In a way that involves a small part or portion of something.
The price was fractionally lower than last year.
Fractionally → It is formed from "fractio" (from Latin, meaning a breaking) and the suffix "-al" (meaning pertaining to) combined with the adverbial suffix "-ly" (meaning in a manner). The word "fractionally" means in a manner pertaining to a break or a part of something.
Think of 'breaking' ('fractio') something into parts to remember that 'fractionally' refers to something done in parts or portions.