Ring, ring, ring - being incredibly tolerant to start with (5)
I believe the answer is:
orbit
'ring' is the definition.
(thesaurus)
'ring ring being incredibly tolerant to start with' is the wordplay.
'ring' becomes 'o' ().
'to start with' says to take the initial letters.
The first letters of 'ring being incredibly tolerant' is 'rbit'.
'o'+'rbit'='ORBIT'
(Other definitions for orbit that I've seen before include "Revolve round" , "Circumnavigate" , "Area of influence - eye socket" , "Moon's track" , "Satellite's path" .)