FREAKISHLY
capriciously, freakishly
(adverb) unpredictably; “the weather has been freakishly variable”
Source: WordNet® 3.1
Etymology
Adverb
freakishly (comparative more freakishly, superlative most freakishly)
In a freakish manner.
Source: Wiktionary
FREAKISH
Freak"ish, a.
Definition: Apt to change the mind suddenly; whimsical; capricious.
It may be a question whether the wife or the woman was the more
freakish of the two. L'Estrange.
Freakish when well, and fretful when she's sick. Pope.
– Freak"ish*ly, adv.
– Freak"ish*ness, n.
Source: Webster’s Unabridged Dictionary 1913 Edition