Run on to the sands (5)
I believe the answer is:
beach
'the sands' is the definition.
(I've seen this before)
I can't explain the remainder of the clue.
Can you help me to learn more?
(Other definitions for beach that I've seen before include "Sands" , "Sandy sea shore" , "Seaside" , "Area by sea" , "Sloping part of shore" .)