by heart

基本解释

This would mean diets with less saturated fat and fewer premature deaths caused by heart disease, they write.
他們指出這樣就降低了飲食中的飽和脂肪酸和由心髒疾病導致的嬰幼兒夭折。
In several studies, this test alerted doctors to over 90 percent of people with atrial fibrillation, as confirmed by heart monitoring.
在幾項研究中，經心髒監測証實，這個測試讓毉生注意到，超過90%的人患有房顫。
Most of us in this country--all who were raised here--know the words and music of our National Anthem by heart.
我們國家裡大部分的人，和在這個國家長大的人，對於這首國歌的曲調和歌詞都已爛熟於心。

For example, your body reacts to stressful situations by raising your blood pressure and making your heart work harder.
Second thing, we started talking about the periodic table and I believe that it's a hallmark of any educated person in the 21st century who is technically literate to know the periodic table by heart.
第二點，我們之前討論過元素周期表,我相信這是個標志性的特征,對於那些在21世紀裡,用心去學習,元素周期表的人來說。
麻省理工公開課 - 固態化學導論課程節選
But in your heart you know it can't be done by today.
但你心裡清楚今天是不可能做完的。
I don't know 課堂 - SpeakingMax英語口語達人

The songs I knew by heart penetrated me as I sat there trying to deafen myself.
NEWYORKER: Mr. Bones