Maybe lying at home because trek endless (9)
I believe the answer is:
insincere
'maybe lying' is the definition.
(someone insincere might be deceitful)
'home because trek endless' is the wordplay.
'home' becomes 'in' ('he's home' can mean 'he's in').
'because' becomes 'since' (I've seen this before).
'endless' indicates the central letters.
The middle letters of 'trek' are 're'.
'in'+'since'+'re'='INSINCERE'
'at' is the link.
(Other definitions for insincere that I've seen before include "is not ringing true" , "tricky" , "Untruthful" , "fake" , "Less than honest" .)