
1) Alternative medicine
Found on
https://www.crosswordclues.com/clue/tar-water

an infusion of tar in water, formerly thought to be a cure-all. Mrs Joe steeps Pip in it in Great Expectations.
Found on
http://charlesdickenspage.com/glossary.html

Tar-water was a medieval medicine consisting of pine tar and water. It was foul-tasting, and so it slowly dropped in popularity, but it was revived in the Victorian era. It is used both as a tonic and as a substitute to get rid of `strong spirits`. Both of these uses were originally advocated by the philosopher George Berkeley, who lauded tar wa.....
Found on
http://en.wikipedia.org/wiki/Tar_water

A cold infusion of tar in water, formerly regarded as a cure-all. (webster, 3d ed) ... (12 Dec 1998) ...
Found on
http://www.encyclo.co.uk/local/20973
No exact match found.