Rate adjusted to accommodate ten more (5)
I believe the answer is:
extra
'more' is the definition.
(I've seen this before)
'rate adjusted to accommodate ten' is the wordplay.
'adjusted' is an anagram indicator.
'to accommodate' indicates putting letters inside.
'ten' becomes 'x' (roman numeral).
'rate' anagrammed gives 'etra'.
'etra' going around 'x' is 'EXTRA'.
(Other definitions for extra that I've seen before include "Additional, like non-speaking actor" , "Additional or supplementary" , "Sundry" , "Minor player in film" , "Taxer (anag.)" .)