Opening a Nut Shell
This page is the CodyCross answer for the clue below from Greece, Group 671, Puzzle 1 (Homer and Sophocles).
Question is: Opening a Nut Shell
and the answer is: CRACKING
Word Meaning:
CRACKING — (organic chemistry, petrochemistry) The thermal decomposition of a substance, especially that of crude petroleum in order to produce petrol / gasoline.
Definitions from Wiktionary.