This is the 5051st most frequent Japanese word.
虜
Captive; prisoner; someone taken or held against their will.
Here, 虜 is used metaphorically to express being captivated or charmed by something emotionally.
彼は彼女の笑顔の虜になった。
He became captivated by her smile.
In this sentence, 虜 represents the literal meaning of 'prisoner,' referring to someone held captive during a conflict.
その王国の虜となった兵士たちは解放された。
The soldiers who became prisoners of that kingdom were freed.
Here, 虜 is used to figuratively describe the effect of engrossing or mesmerizing an audience.