Welshman doesn't tell the truth in newspapers (7)
I believe the answer is:
dailies
'newspapers' is the definition.
(daily is a kind of newspaper)
'welshman doesn't tell the truth' is the wordplay.
'welshman' becomes 'Dai' (Welsh name).
'doesn't tell the truth' becomes 'lies' (I've seen this in another clue).
'dai'+'lies'='DAILIES'
'in' is the link.
(Other definitions for dailies that I've seen before include "employed in cleaning?" , "Rags" , "Newspapers" .)