予防線 (よぼうせん)defensive perimeter; defence line; defense line

予防線, its kanji, and other words that share them.Open this graph

Kanji in 予防線

予定よていplans; arrangement
予算よさんestimate; budget
予想よそうexpectation; anticipation
予選よせんpreliminary contest; qualifying round
予備よびreserve; spare
予測よそくprediction; estimation
予防よぼうprevention; precaution
補正予算ほせいよさんrevised budget; supplementary budget
防衛ぼうえいdefense; defence
国防こくぼうnational defence; national defense
防止ぼうしprevention; check
防衛庁ぼうえいちょうJapan Defense Agency (became Ministry of Defense in January 2007)
攻防こうぼうoffense and defense; offence and defence
消防しょうぼうfire fighting
防災ぼうさいdisaster preparedness; prevention of damage resulting from a natural disaster
路線ろせんroute (bus, train, air, etc.); line
打線だせんbatting lineup (line-up)
新幹線しんかんせんShinkansen; bullet train

See how 予防線 connects to the rest of Japanese.