A Riddle or Problem That's Difficult to Solve
This page is the CodyCross answer for the clue below from Apothecary, Group 1966, Puzzle 3 (Decoctions).
Question is: A Riddle or Problem That's Difficult to Solve
and the answer is: CONUNDRUM
Word Meaning:
CONUNDRUM — A difficult question or riddle, especially one using a play on words in the answer.
Definitions from Wiktionary.