adverb
Used to emphasize that something is nothing more than what is stated; often carries a nuance of 'just' or 'no more than'. Common in negative contexts or when downplaying something.
それはただに噂に過ぎない。
That is merely a rumor.
彼はただに驚いただけだ。
He was simply surprised.
Derived from the noun/adverb ただ (only, just) with the adverbial particle に. The kanji forms are ateji and rarely used.