godan verb (-su), intransitive verb
Used for paying careful attention to something, often with a sense of caution or mindfulness. Cross-referenced with 心する, which is a more common synonymous expression.
See also: 心する
言葉遣いに心して話してください。
Please be mindful of your language when you speak.
彼は健康に心して生活している。
He lives his life taking care of his health.