欄外 is read as らんがい (rangai) and means margin.
らんがい
rangai
らんかん
(flowing) endlessly (of tears)
らんま
transom
あんがい
unexpectedly
そがい
alienation
けんがい
outside (a region, area, etc.)
しょうがい
public relations
わくがい
(beyond the) limits
かくがい
outside the Cabinet
きそうてんがい
fantastic
ぼがい
unaccounted
はいがい
anti-foreign
きほんがい
non-basic