Clueless going in and out of love nest (4)
I believe the answer is:
lost
'clueless' is the definition.
(thesaurus)
I cannot understand how the rest of the clue works.
Can you help me to learn more?
(Other definitions for lost that I've seen before include "Baffled" , "Mogul empire official; rich person" , "Mislaid or astray" , "Mislaid or irretrievable" , "Unable to find the way forward" .)