Kind of dash about on lake (4)
I believe the answer is:
mere
'lake' is the definition.
(mere is a kind of lake)
'kind of dash about on' is the wordplay.
'kind of dash' becomes 'me' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'about' becomes 're' (regarding).
'on' means one lot of letters go next to another.
'me'+'re'='MERE'
Can you help me to learn more?
(Other definitions for mere that I've seen before include "Lake in Cumbria" , "Paltry" , "Pool, small lake" , "Lake - French mother" , "Bare, simple" .)