Man providing a lift at regular intervals (3)
I believe the answer is:
alf
'man' is the definition.
(I've seen this before)
'a lift at regular intervals' is the wordplay.
'at regular intervals' means one should take alternating letters.
The alternate letters of 'lift' are 'lf'.
'a'+'lf'='ALF'
'providing' is the link.
(Other definitions for alf that I've seen before include "Chap" , "Sir - Ramsey, England footballer and manager" , "Great king briefly" , "See man" , "-- Garnett, bigoted TV?character" .)