| そ | 
|---|
| 遡 | 
| こ | う | 
|---|---|
| 行 | 
noun, takes する, intransitive verb
- going upstream, sailing against the current.
Variations
| Pronunciation | Kanji | Kana | Is Common | |||||
|---|---|---|---|---|---|---|---|---|
| 
 
 | 遡行 | そこう | ||||||
| 
 
 | 溯行 | そこう | ||||||
| 
 
 | 遡航 | そこう | ||||||
| 
 
 | 溯航 | そこう | 
Contained Kanji Breakdown
go upstream, retrace the past
さかのぼ.る ソ サク (11th)
conjunction (astronomy), first day of month, north
ついたち サク たち (Kentei Pre-1, N1)