始終|しじゅうshijuu[1]atamadaka (head-high)

1. adverb, nouncontinuously; from beginning to end; from first to last
   私は始終しじゅうあなたのことを考かんがえています。↗

   You are in my thoughts at all times.

• Synonym絶えずたえずNeutralStresses unbroken continuity — 「絶えず努力する」. 「始終」 also carries the sense of 'all the time, at every turn'.
• SynonymとめどなくNeutralDescribes something that will not stop — 「涙がとめどなく流れる」; not a general adverb for 'always'.
• Synonym絶え間なくたえまなくNeutralAn action continuing without a break — 「絶え間なく雨が降る」; the focus is the unbroken stretch itself.
• SynonymしょっちゅうCasualColloquial: always, constantly — 「しょっちゅう遅刻する」; 「始終」 is slightly more formal.
• SynonymいつもNeutralThe everyday default for 'always' — 「いつも遅い」; the most common choice in speech.
• Synonym四六時中しろくじちゅうNeutralAround the clock, day and night — 「四六時中スマホを見る」; hyperbolic, where 「始終」 is plainer.
• Synonym常につねにNeutralAlways, at all times — 「常に注意する」; leans written and formal.
• SynonymいつでもNeutral'Any time is fine' — 「いつでもどうぞ」; availability at any moment, not continuous duration.
• Synonym常々つねづねWrittenWritten style for what one habitually thinks or does — 「常々思う」; 「始終」 covers start-to-finish or 'always'.
• Synonym間断なくかんだんなくWrittenWritten style and rarely used: without interruption, continuously.
• SynonymのべつまくなしCasualColloquial, for nonstop, never-ending action — 「のべつ幕なしに喋る」; 「始終」 is the more neutral choice.
• Synonym引きも切らずひきもきらずWrittenWritten style for a steady, unbroken stream, as of visitors — 「客が引きも切らず」; 「始終」 stresses 'the whole time, always'.
• RelatedしきりにNeutralRepeatedly, frequently — 「しきりに頷く」; about repeated occurrences rather than one continuous span.
• Related年中ねんじゅうNeutralAll year round — 「年中無休」; the span is a whole year.
• Related明け暮れあけくれNeutralSpending one's days absorbed in something — 「練習に明け暮れる」; about devoting one's time, not plain continuity.
• Related頻繁ひんぱんNeutralFrequent, at short intervals — 「頻繁に起こる」; an objective measure of how often, not a continuous span.
• RelatedちょくちょくCasualColloquial: now and then, fairly often — 「ちょくちょく来る」; lower frequency than 「始終」.
• RelatedちょいちょいCasualColloquial with a light, casual feel: now and then; lower frequency than 「始終」.
• RelatedしばしばWrittenWritten style: often, repeatedly — 「しばしば見られる」; 「始終」 stresses continuous duration or constancy.
• RelatedたびたびNeutralRepeatedly, many times — 「たびたび遅れる」; counts recurrences, not an unbroken span.
• Related決まってきまってNeutralInvariably, every single time — 「決まって雨が降る」; the point is 'without fail'.
• Related年がら年中ねんがらねんじゅうCasualColloquial: all year round, all the time — often with exaggerated complaint.
• RelatedしげしげNeutralFrequently, or gazing closely and fixedly — 「しげしげと見る」; the gazing sense is separate from duration.
• Related常住坐臥じょうじゅうざがWrittenFour-character idiom, strongly literary: at all times, within one's daily life, sitting or lying.
• Related年百年中ねんびゃくねんじゅうCasualColloquial and rare: all year round, always.
• RelatedしきりとNeutralA variant of 「しきりに」: frequently, eagerly; slightly written — in everyday speech 「しきりに」 is the usual form.
• Related常住じょうじゅうWrittenBuddhist term for eternal, unchanging existence; also living permanently in one place; rare.
• AntonymひとときNeutralA short while, a brief moment — the opposite pole to 「始終」's continuous span.
• Antonym一時いちじNeutralAs 「一時」: a short time, or some period in the past; its brevity is what contrasts with 「始終」.

Use 「始終」 for something from start to finish (「一部始終」) or for 'always, constantly' (「始終笑っている」). In daily speech, 'always' is 「いつも」, 'frequently' 「しょっちゅう」, unbroken continuity 「絶えず」, 'around the clock' 「四六時中」. Most other words here are about frequency (「しきりに」, 「たびたび」, 「ちょくちょく」) or year-round spans (「年中」, 「年がら年中」), and many are marked colloquial or written. 「ひと時」, a brief moment, is the opposite of 「始終」.

Usage comparisons are AI-assisted and cross-checked by multiple models; for study reference only

1. 始はじめから終おわりまで、ずっと。
2. いつも。