Tailor with a type of accommodation up on square (5)
I believe the answer is:
adapt
'tailor' is the definition.
(thesaurus)
'a type of accommodation up on square' is the wordplay.
'type of accommodation' becomes 'pad' (I can't justify this - if you can you should give a lot more credence to this answer).
'up' says the letters should be written in reverse (in down clue: letters go upwards).
'on' says to put letters next to each other.
'square' becomes 't' (a T-Square is a technical drawing instrument).
'pad' in reverse letter order is 'dap'.
'a'+'dap'+'t'='ADAPT'
'with' acts as a link.
Can you help me to learn more?
(Other definitions for adapt that I've seen before include "Adjust to new use" , "Become adjusted to new circumstances" , "Change to suit a different purpose" , "Adjust to new circumstances" , "Accommodate" .)