adverb, adverb taking the 'to' particle
Internet slang onomatopoeic adverb meaning something is exactly right, perfectly timed, or hits the mark. Often used with と.
See also: バッチリ
このタイミング、バチコリ合ってる。
This timing is spot on.
彼の答えはバチコリと当たっていた。
His answer was bang on.