noun
ebb tide; falling tide
Refers to the outgoing or receding tide, the period when the sea level is falling.
下げ潮のときに、遠くの岩場まで歩いて行ける。
When the tide is going out, you can walk out to the distant rocks.
漁師は下げ潮を狙って船を出した。
The fisherman set out aiming for the ebb tide.
Compound of 下げ (sage, 'lowering') + 潮 (shio, 'tide'). The reading さげしお is a straightforward combination of the kun'yomi readings of the two kanji.