Like a shoe, perhaps, that's unsafe to walk on (8)
I believe the answer is:
slippery
This clue is a double definition.
'like a shoe perhaps' is the first definition.
(like a slipper)
'unsafe to walk on' is the second definition.
(as in a slippery surface)
'that's' acts as a link.
(Other definitions for slippery that I've seen before include "Descent into sin in this sort of slope" , "Untrustworthy" , "Evasive, elusive" , "Not to be trusted" , "Wet, slimy; evasive" .)