mechanical pencil lead
Colloquial abbreviation from シャーペン (mechanical pencil) + 芯 (lead). Common in everyday speech and casual writing.
See also: シャーペン
I ran out of mechanical pencil lead, so I have to buy some more.
This mechanical pencil lead breaks easily.
Colloquial abbreviation from シャーペン (mechanical pencil) + 芯 (lead).