1990-91 World Grand Prix champion (5)
I believe the answer is:
senna
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">1990-91 world grand prix champion</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 senna that I've seen before include "Tropical plant with medicinal leaflets" , "should make you want to go quickly" , "Laxative from pods" , "Natural laxative" , "He drove fast" .)