Crossword Genius

As my spot could be with onset of measles? (7)

Ross

I believe the answer is:

symptom

I'm a little stuck... Click here to teach me more about this clue!

'as' is the definition.
Although both the answer and definition are singular nouns, I don't understand how they can define each other.

'my spot could be with onset of measles?' is the wordplay.
'could be with' indicates an anagram.
'onset of' says to take the initial letters.
The initial letter of 'measles' is 'm'.
'my'+'spot'='myspot'
'myspot' anagrammed with 'm' can make 'SYMPTOM'.

Can you help me to learn more?

(Other definitions for symptom that I've seen before include "Evidence for disease" , "Indicator of disease" , "Expression" , "sign all's not well" , "Prodrome" .)

Want a hint initially instead of a full solution? Install my app