(pos:名詞)yue:一種書寫工具;介乎於用水性墨嘅#墨水筆 同用油性墨嘅#原子筆 之間,筆芯裝住中性墨水,筆尖有一粒鐵珠塞住開口,寫嘢嗰陣粒鐵珠會跟住筆尖嘅郁動,轆啲墨水落張紙上面(量詞:枝/支)eng:rollerball pen