Mortice is designed with the same dimensions (9)
I believe the answer is:
isometric
'mortice is designed with the same dimensions' is the definition.
I can't tell whether this definition defines the answer.
'mortice is designed' is the wordplay.
'designed' indicates anagramming the letters (designed with the letters).
'mortice'+'is'='morticeis'
'morticeis' anagrammed gives 'ISOMETRIC'.
Can you help me to learn more?
(Other definitions for isometric that I've seen before include "form of exercise" , "regarding muscular action" , "equal in measurement" , "Type of exercise performed against resistant object" , "of equal size" .)