It might be rash to touch them (7)
I believe the answer is:
nettles
'them' is the definition.
I can't tell whether this definition defines the answer.
'it might be rash to touch' is the wordplay.
'it might be' becomes 's' (I can't justify this - if you can you should believe this answer much more).
'rash' becomes 'nettle rash' (nettle rash is a kind of rash).
'to touch' says to put letters next to each other.
's' after 'nettle' is 'NETTLES'.
Can you help me to learn more?
(Other definitions for nettles that I've seen before include "Plants with stinging hairs" , "One acting Chief Inspector on TV" , "Irritates" .)