Occurring every other year (8)
I believe the answer is:
biennial
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">occurring every other year</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 biennial that I've seen before include "Two-yearly" , "Plant living two years" , "Taking place every other year" , "Happening every second year" , "Plant with a two-year life cycle" .)