Archaeological period
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">archaeological period</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this before)</span><br/ ><br/ >This is all the clue.<br/ ></span>
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">archaeological period</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this before)</span><br/ ><br/ >This is the entire clue.<br/ ></span>
(Other definitions for iron age that I've seen before include "Archaeological period" , "bygone era" , "prehistoric times" , "historical period" , "Hist. cultural stage" .)