long speech; monologue
Refers to a lengthy spoken part in a play, film, or conversation; often implies a single person talking at length.
No one interrupted until his long speech was over.
That actor had perfectly memorized the long monologue.
独白 is a more formal or literary term for a soliloquy or monologue, often used in theater analysis, whereas 長台詞 is a common, everyday word for any long speech.
Standard kanji spelling.
Mixed kanji-katakana spelling, common in manga and informal contexts.
Compound of 長 (long) and 台詞 (speech, line). The reading ながぜりふ follows standard rendaku voicing of せりふ to ぜりふ in compounds.