Colloquial adverb expressing that something is surprisingly or unreasonably intense, excessive, or out of the ordinary. Often carries a nuance of 'more than expected' or 'strangely'.
やけに and やたら can both intensify an adjective to mean 'unusually/excessively', but やけに carries a stronger sense of surprise at an unexpected degree, while やたら simply marks excess or lack of restraint.
Etymology
Derived from 自棄 (やけ, 'desperation, self-abandonment'), with the adverbial particle に. The original sense of 'desperately' softened into a colloquial intensifier.
