Floating agnostic is drifting (8)
I believe the answer is:
coasting
'drifting' is the definition.
The definition and answer can be both to do with motion as well as being present participle verbs.
Perhaps they are linked in a way I don't understand?
'floating agnostic' is the wordplay.
'floating' is an anagram indicator (float can mean fluctuate or oscillate).
'agnostic' is an anagram of 'COASTING'.
'is' is the link.
Can you help me to learn more?
(Other definitions for coasting that I've seen before include "Agnostic (anag) -- moving easily" , "Just rolling along with agnostic" , "Not trying all that hard" .)