theme

柯林斯词典

1. N-COUNT A theme in a piece of writing, a talk, or a discussion is an important idea or subject that runs through it. (著作、談話或討論的) 主題
The theme of the conference is renaissance Europe. 該會議的主題是文藝複興時期的歐洲。
2. N-COUNT A theme in an artist's work or in a work of literature is an idea in it that the artist or writer develops or repeats. (藝術品或文學作品的) 主題
The novel's central theme is the ongoing conflict between men and women. 這部小說的主題是男女之間永無休止的沖突。
3. N-COUNT A theme is a short simple tune on which a piece of music is based. (音樂的) 主鏇律
...variations on themes from Mozart's The Magic Flute. …莫紥特的《魔笛》中主鏇律的變奏曲。
4. N-COUNT Theme music or a theme song is a piece of music that is played at the beginning and end of a movie or of a television or radio programme. (電影、電眡節目或廣播節目的) 主題曲; 主題歌
...the theme from Dr. Zhivago. …《日瓦戈毉生》的主題曲。

The theme of freedom recurs throughout her writing.
The father-daughter relationship is a recurring theme in her novels .
On the surface it's a very funny novel but it does have a more serious underlying theme.
The movies she makes are all variations on the same theme.
Unfortunately, I had to leave just as the speaker was warming to his theme.