In certain directions, a broken limb is freely mobile (6)
I believe the answer is:
nimble
'freely mobile' is the definition.
'nimble' can be an answer for 'mobile' (thesaurus). I am unsure of the 'freely' bit.
'in certain directions a broken limb' is the wordplay.
'in' indicates putting letters inside.
'certain directions' becomes 'ne' (I've seen this in other clues. I am not sure about the 'certain' bit.).
'a broken' indicates anagramming the letters.
'limb' anagrammed gives 'imbl'.
'ne' enclosing 'imbl' is 'NIMBLE'.
'is' is the link.
Can you help me to learn more?
(Other definitions for nimble that I've seen before include "Moving quickly and lightly" , "Quick on the feet" , "Fast; light in movement" , "'Agile, spry (6)'" , "Agile, sprightly" .)