Give a boost (4)
I believe the answer is:
help
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">give a boost</span>' is the definition.<br/ ><span class="explanation-format__explanation">(thesaurus)</span><br/ ><br/ >This is the entire clue.<br/ ></span>
(Other definitions for help that I've seen before include "Charity" , "Contribute to the success of" , "Take what you want" , "Come to the aid of" , "Succour" .)