Ring back in no more than 59 seconds? (6)
I believe the answer is:
nimbus
'ring' is the definition.
(thesaurus)
'back in no more than 59 seconds?' is the wordplay.
I cannot quite see how this works, but
'no' could be 'n' (common abbreviation) and 'n' is present in the answer.
'more' could be 'm' and 'm' is found within the answer.
'seconds?' could be 's' and 's' is found in the answer.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for nimbus that I've seen before include "Bums in (anag)" , "A kind of rain-cloud, or 15 Across" , "Type of rain cloud" , "showers under it" , "Dirty cloud; saintly light" .)