C1 adverb /ˈwɪmzɪkli/
Whimsically
遊び心いっぱいに
Meaning
In a playful, fanciful, or capricious manner; with sudden changes of mind
Example
She decorated her room whimsically with colorful balloons.
彼女は部屋をカラフルな風船で遊び心いっぱいに飾った。