noun
line; spoken line
Refers to a character's spoken line in a play, film, TV show, comic, etc. Often used in the plural sense of 'one's lines'.
彼は舞台でセリフを忘れてしまった。
He forgot his lines on stage.
この映画のセリフはとても印象的だ。
The lines in this movie are very memorable.
noun
Used for something someone says, often with a nuance of being a notable or characteristic remark. Can be used in everyday conversation.
彼のセリフにはいつも驚かされる。
I'm always surprised by the things he says.
そんなセリフを言うなんて、らしくないね。
That's not like you to say something like that.
noun
stock phrase; cliché; platitude
Refers to a predictable or overused phrase, often with a negative or ironic nuance. Common in expressions like お決まりのセリフ (the usual line).
またそのセリフか、と彼はうんざりした。
He was fed up with hearing that same old line again.
政治家のお決まりのセリフにはもう慣れた。
I've gotten used to politicians' stock phrases.