accumulatively

Etymology tree
Proto-Indo-European *h₂éd
Proto-Italic *ad
Proto-Italic *ad-
Latin ad-
Proto-Indo-European *ḱewh₁-
Proto-Indo-European *ḱuh₁mósder.?
Latin cumulus
Proto-Indo-European *-h₂
Proto-Indo-European *-éh₂
Proto-Indo-European *-yéti
Proto-Indo-European *-eh₂yéti
Proto-Italic *-āō
Latin -ō
Latin cumulō
Latin accumulō
Latin accumulātusbor.
Middle English accumylaten
English accumulate
Proto-Indo-European *-wós
Proto-Indo-European *-iHwósder.
Latin -īvus
Old French -ifbor.
Middle English -yf
English -ive
English accumulative
Proto-Indo-European *leyg-der.
Proto-Germanic *līkąder.
Proto-Germanic *-līkaz
Proto-Germanic *-ê
Proto-Germanic *-līkê
Proto-West Germanic *-līkē
Old English -līċe
Middle English -ly
English -ly
English accumulatively
From accumulative + -ly.