Where one might find H readily available (2,3)
I believe the answer is:
on tap
'readily available' is the definition.
(I've seen this before)
I cannot understand how the rest of the clue works.
Can you help me to learn more?
(Other definitions for on tap that I've seen before include "Readily available" , "where C or H is seen?" , "Where you may see H or C" , "kept in a cask" , "Constantly available like beer from keg" .)