Fluid in plants (3)
I believe the answer is:
sap
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">fluid in plants</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 sap that I've seen before include "Gradually weaken (a person's strength)" , "The juice in trees" , "Plant juice for silly ass" , "Weak foolish person" , "Plant juice; undermine" .)