From jumbled + -ly.
jumbledly (comparative more jumbledly, superlative most jumbledly)
- In a jumbled manner.
1988 June 3, Albert Williams, “Soul Rapture”, in Chicago Reader[1]:The costumes should be a key device to charting the passage of time and trends in this show, but Julie Jackson's designs are a confusing clutter of styles, tackily manufactured, and jumbledly arranged.