Dictionary Definition :
Definition[1]
:
Under three rafters—the regulation space for a monk's bed or seat; in meditation.
Source
:
A Dictionary of Chinese Buddhist Terms, William Edward Soothill and Lewis Hodous
Definition[2]
:
(雜語)僧堂之床,每人之座位橫占三尺許,其頭上之椽有三條,因指禪床曰三條椽下。碧巖二十五則評曰:「[何-可+爾]諸人若見得與蓮華峰庵主同參,其或未然三條椽下七尺,單前試去參詳看。」
Source
:
丁福保《佛學大辭典》