オープニング

オ

ー

プ

ニ

ン

グ

Common wordFreq.FrequencyTop 10,000

Meanings

General term for the beginning of an event, ceremony, or activity. Often used in formal or event contexts.

opening credits; title sequence

abbreviation

Abbreviation of オープニングタイトル or similar. Refers specifically to the opening credits or title sequence of a TV show, movie, or video.

〈事こと〉のオープニングを飾かざるto grace/highlight the opening of an event
有ゆう名めい歌か手しゅが式しきのオープニングを飾かざった。
A famous singer graced the opening of the ceremony.
オープニングが始はじまるthe opening (of an event/show) begins
会かい場じょうが暗くらくなり、オープニングが始はじまった。
The venue went dark, and the opening began.
オープニングが流ながれるthe opening theme (song) plays
テレビをつけると、アニメのオープニングが流ながれていた。
When I turned on the TV, the anime's opening theme was playing.

開かい始しN3sense 1
オープニング is a casual loanword for the start of an event, while 開始 is the more formal, native Japanese term for 'commencement'.
ＯＰ
オープニング is the full loanword for any kind of opening (ceremony, event, credits), while ＯＰ is the clipped form used specifically for anime/TV title sequences and theme songs.

エンディング
オープニング marks the beginning of an event, show, or theme song, while エンディング marks its end.
フィナーレ
オープニング is the opening of an event or show, the direct opposite of フィナーレ, its grand closing.

From English 'opening'. The abbreviated senses for credits and theme song are Japanese-specific developments.