悪性(あくせい) あくせい noun, no-adjective malignant; vicious; virulent formalhealth 1. malignant; vicious; virulent Of a disease or growth, dangerous and tending to get worse or spread; more broadly, of a harmful, vicious kind. Mainly a medical word. 検査(けんさ)の結果(けっか)、悪性(あくせい)ではなかった。 The tests showed it was not malignant. 悪性(あくせい)の腫瘍(しゅよう)が見(み)つかった。 A malignant tumor was found. 今年(ことし)は悪性(あくせい)のインフルエンザが流行(りゅうこう)しているので、注意(ちゅうい)が必要(ひつよう)だ。 A virulent strain of influenza is going around this year, so care is needed. Common collocations悪性(あくせい)腫瘍(しゅよう): malignant tumor悪性(あくせい)リンパ腫(しゅ): malignant lymphoma悪性(あくせい)の風邪(かぜ): a nasty coldSimilar words良性(りょうせい): benign (the opposite)悪質(あくしつ): vicious, malicious (of people and their actions: 悪質(あくしつ)な詐欺(さぎ)); 悪性(あくせい) is used for diseases Related Words Antonym: 良性(りょうせい) (benign) Compare: 悪質(あくしつ) (vicious, malicious (of people and their…) general Added 2026.10.16 23:01 · Revised 2026.10.16 23:02 32000/32060_akusei