Nothing in noblewoman's coat seen floating beside spectre's face? Tosh! (8)
I believe the answer is:
nonsense
'tosh' is the definition.
(tosh can mean nonsense or rubbish)
'nothing in noblewoman's coat seen floating' is the wordplay.
'nothing' becomes 'no' (similar in meaning).
'in' means one lot of letters goes inside another.
'coat' suggests removing the centre (only the letters which coat the word are used).
'floating' indicates an anagram (float can mean fluctuate or oscillate).
'noblewomans' with its centre removed is 'ns'.
'ns'+'seen'='nsseen'
'nsseen' anagrammed gives 'nsense'.
'no' put into 'nsense' is 'NONSENSE'.
'beside spectre's face?' is the link.
I am not very happy about this link. Some or all of it may belong to another bit of the clue.
Can you help me to learn more?
(Other definitions for nonsense that I've seen before include "folly" , "Codswallop, hooey" , "Rubbish, drivel" , "Rubbish, rot" , "Rubbish; absurdity" .)