### Clue: Old Saxon lawgiver one for eastern assimilation (7)
### Answer: OSMOSIS 
 ### Explanation: Old Saxon lawgiver one for eastern assimilation (7)
**O** (old) + **S** (Saxon) + **MOS**(e>**i**)**S** ("lawgiver" with I ("one") *for* (i.e. replacing) E (eastern))