警戒|けいかいkeikai[0]heiban (flat)
This browser can't play pronunciations (needs Safari 18.4 or later, or Chrome / Edge / Firefox).
Definitions
- noun, suru verb, transitive verbvigilance; caution; alertness; precaution; being on guard
Conjugation
| Dictionary form | 警戒する（けいかいする） |
|---|---|
| Polite (masu) | 警戒します（けいかいします） |
| Negative (nai) | 警戒しない（けいかいしない） |
| polite (masen) | 警戒しません（けいかいしません） |
| classical zu / nu | 警戒せず・警戒せぬ（けいかいせず・けいかいせぬ） |
| Past (ta) | 警戒した（けいかいした） |
| polite (mashita) | 警戒しました（けいかいしました） |
| Past negative (nakatta) | 警戒しなかった（けいかいしなかった） |
| polite (masen deshita) | 警戒しませんでした（けいかいしませんでした） |
| Te form | 警戒して（けいかいして） |
| Potential | 警戒できる（けいかいできる） |
| Passive | 警戒される（けいかいされる） |
| Causative | 警戒させる（けいかいさせる） |
| Causative passive | 警戒させられる（けいかいさせられる） |
| Conditional (ba) | 警戒すれば（けいかいすれば） |
| tara | 警戒したら（けいかいしたら） |
| Volitional | 警戒しよう（けいかいしよう） |
| polite (mashou) | 警戒しましょう（けいかいしましょう） |
| Imperative | 警戒しろ（けいかいしろ） |
Common forms generated by rule; see the senses for honorific or irregular usage.
Synonyms & antonyms
- Synonym用心ようじんNeutralNeutral noun for personal caution, as in 「火の用心」. Common in speech and focused on guarding oneself; for everyday wariness it can stand in for 「警戒」.
- Synonym注意ちゅういNeutralNeutral noun with the broadest range: attention, heeding, or a warning, as in 「注意してください」. Unlike 「警戒」 it need not involve danger at all.
- Synonym警護けいごWrittenWritten/formal noun for close protection of important people, as in 「要人警護」. Narrower than 「警戒」: bodyguarding a person rather than staying alert to danger.
- SynonymガードCasualColloquial loanword for guarding or defense, as in 「ボディーガード」. Casual register; use 「警戒」 for the alert itself.
- Related警備けいびWrittenWritten/formal noun for professional security—guarding and patrolling, as in 「警備員」. It names the guarding work itself, not the state of alert in 「警戒」.
- Related監視かんしWrittenWritten/formal noun for surveillance, as in 「監視カメラ」. It stresses close watching; 「警戒」 stresses readiness for danger.
- Related見守るみまもるNeutralNeutral verb for watching over someone or quietly observing how things unfold, as in 「成長を見守る」「推移を見守る」. Protective or expectant watching, not alertness to danger.
- Related防衛ぼうえいWrittenWritten/formal noun for defense against attack, as in 「国の防衛」「正当防衛」. It is about warding off aggression, not the vigilance of 「警戒」.
- Related守備しゅびWrittenWritten/formal noun for defense in sports or military settings, as in 「守備範囲」. Fielding or holding a line—nothing like the alertness of 「警戒」.
- Related防護ぼうごWrittenWritten/formal noun for protection from harm, as in 「防護服」. It centers on shielding against injury; 「警戒」 is the alertness beforehand.
- Related護衛ごえいWrittenWritten/formal noun for escorting and guarding, as in 「護衛艦」. It is about accompanying and protecting someone or something, not the watchful state of 「警戒」.
- Related守護しゅごWrittenWritten/formal noun for protection or guardianship, as in 「守護神」; also names a historical military-governor office. Not a substitute for 「警戒」.
- Related防備ぼうびWrittenWritten/formal noun for defensive preparations against enemies or disaster, as in 「防備を固める」. The preparations themselves, not the alertness of 「警戒」.
- Related戒心かいしんWrittenWritten/formal word for a wary, guarded state of mind. Rare in modern Japanese; 「警戒」 or 「用心」 is normally used instead.
- Antonym油断ゆだんNeutralNeutral noun for carelessness or letting one's guard slip—the direct opposite of 「警戒」.
Use 「警戒」 for heightened vigilance against danger, as in 「警戒警報」. For personal caution pick 「用心」 or 「注意」; for professional security 「警備」; for guarding VIPs 「警護」; for surveillance 「監視」. The 「防衛」/「守備」/「防護」 group covers defense and protection, not alertness; 「油断」 is the opposite—letting your guard down.
Usage comparisons are AI-assisted and cross-checked by multiple models; for study reference only
Japanese definitions
Kanji in this word
English equivalents
See also
