Losing time tailing bent criminal that's elusive (10)
I believe the answer is:
intangible
'elusive' is the definition.
('intangible' can be a synonym of 'elusive')
'losing time tailing bent criminal' is the wordplay.
'losing' indicates named letters should be taken away.
'time' becomes 't'.
'criminal' is an anagram indicator.
'tailing'+'bent'='tailingbent'
'tailingbent' with 't' taken out is 'ailingbent'.
'ailingbent' is an anagram of 'INTANGIBLE'.
'that's' acts as a link.
(Other definitions for intangible that I've seen before include "unclear" , "Abstract - hard to grasp" , "Elusive" .)