彼らはいっせいに叫んだ。

彼らはいっせいに叫んだ。

They cried out with one voice.

彼(かれ)らはいっせいに叫(さけ)んだ。

Karera wa isseini sakenda.

彼ら (かれら)

they (usually male); them

は (は)

topic marker particle; indicates contrast with another option (stated or unstated); adds emphasis

一斉に (いっせいに)

simultaneously; all at once

叫ぶ (さけぶ)

to shout; to cry; to scream; to shriek; to yell; to exclaim; to clamor (for or against); to clamour (for or against)

Readings: ヒ、かれ、かの、か.の

Meanings: he, that, the

Readings: キョウ、さけ.ぶ

Meanings: shout, exclaim, yell