Training or diets that may boost performance? (7)
I believe the answer is:
steroid
'may boost performance?' is the definition.
Although both the answer and definition are singular nouns, I don't understand how they can define each other.
'training or diets' is the wordplay.
'training' indicates anagramming the letters (to train can mean to grow something into a shape).
'or'+'diets'='ordiets'
'ordiets' is an anagram of 'STEROID'.
'that' is the link.
Can you help me to learn more?
(Other definitions for steroid that I've seen before include "Performance-enhancer illegal for athletes" , "Organic compound" , "muscle-building compound" , "Type of hormone" , "Hormone perhaps" .)