Tough nut to crack (5)
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">tough nut to crack</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this in another clue)</span><br/ ><br/ >This is the entire clue.<br/ ></span>
(Other definitions for acorn that I've seen before include "cup's content" , "Source of a great oak" , "old computer?" , "Fruit of the oak tree" , "from which something bigger may develop" .)
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">tough nut to crack</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this in another clue)</span><br/ ><br/ >This is the entire clue.<br/ ></span>
(Other definitions for poser that I've seen before include "Question - a sitter" , "Tricky clue" , "Difficult problem" , "Show-off" , "Artist's model" .)
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">tough nut to crack</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this in another clue)</span><br/ ><br/ >This is all the clue.<br/ ></span>
(Other definitions for enigma that I've seen before include "Solution to mystery" , "Gamine being a bit of a puzzle" , "German military cipher machine" , "It's mysterious like gamine" , "WW2 code" .)