Dictionary Definition :
Definition[1]
:
The four monastic annual periods — beginning of summer, end of summer, winter solstice, and the new year.
Source
:
A Dictionary of Chinese Buddhist Terms, William Edward Soothill and Lewis Hodous
Definition[2]
:
四節===(名數)禪林於結夏,解夏,冬至,年朝,謂之四節。義堂日工集曰:「凡稱四節,乃百丈業林也。結解則天竺佛制,冬年則中華俗節。百丈以隨方毘尼,禮貴同俗,遂有四大節之儀。」
Source
:
丁福保《佛學大辭典》