Hour in work provides excitement (6)
I believe the answer is:
thrill
'excitement' is the definition.
(thrill is a kind of excitement)
'hour in work' is the wordplay.
'hour' becomes 'hr' ('hr' can be a synonym of 'hour').
'in' indicates putting letters inside.
'work' becomes 'till' (tilling is a kind of working).
'hr' put inside 'till' is 'THRILL'.
'provides' acts as a link.
(Other definitions for thrill that I've seen before include "Almost pleasant sensation of fright" , "Stimulating sensation, wave of excitement" , "Exhilarate, excite" , "gas" , "Tingling feeling of excitement" .)