CEDICT
mechanical pencil; propelling pencil; pacer
Wiktionary
一种可更换笔蕊的铅笔。轻压笔杆的顶端,可使笔蕊露出或缩进,并能随意调整长度。
重編國語辭典
一种笔芯可更换并且可以机械伸缩的铅笔
維基詞典
I got a piece of lead for my mechanical pencil from her.
Source: Tatoeba
classifiers: 支, 枝, 桿