Make a Liquid More Dense or Solid
This page is the CodyCross answer for the clue below from Germany, Group 2199, Puzzle 4 (Eifel National Park).
Question is: Make a Liquid More Dense or Solid
and the answer is: THICKEN
Word Meaning:
THICKEN — (transitive) To make thicker (in the sense of wider).
Definitions from Wiktionary.