The beginning and the end; referring to the start and finish of an event or process.
その事件の終始を簡単に説明してください。
Please briefly explain the beginning and end of that incident.
会議の終始が議事録に記録されていた。
The start and finish of the meeting were recorded in the minutes.
Doing something from beginning to end; being unchanged or consistent throughout.
彼は試合の終始を通して冷静だった。
He remained calm throughout the match.
終始一貫して彼はその方針を支持した。
He consistently supported that policy from start to finish.
彼女は終始同じ態度で対応した。
She responded with the same attitude throughout.
As an adverb meaning 'from beginning to end' or 'throughout' (used to describe something happening the whole time).
彼の話は終始面白かった。
His talk was interesting throughout.
彼女は終始笑顔を絶やさなかった。
She didn't stop smiling the whole time.
警察は終始厳しい態度を崩さなかった。
The police maintained a strict attitude throughout.