top; penetrative partner; seme
Slang term used in erotic contexts, especially in BL (boys' love) and adult media, for the character who takes the active, penetrative role. Derived from 竿 (さお, 'rod') + 役 (やく, 'role').
See also: 竿 (さお)
このBL漫画では、竿役のキャラがとても優しい。
In this BL manga, the top character is very gentle.
同人誌の竿役はいつも同じ声優が演じているイメージ
I have the impression that the same voice actor always plays the top in doujinshi.
Compound of 竿 (さお, 'rod, pole') and 役 (やく, 'role, part'). The term likely originated in erotic manga and doujin circles as a euphemistic way to refer to the penetrative partner.