After a month workers finally get increase (7)
I believe the answer is:
augment
'increase' is the definition.
(augmenting is a kind of increasing)
'after a month workers finally get' is the wordplay.
'after' says to put letters next to each other.
'a month' becomes 'aug' (Aug is an example**).
'workers' becomes 'men' (man is a kind of worker).
'finally' indicates one should take the final letters.
The final letter of 'get' is 't'.
'aug' next to 'men' is 'augmen'.
'augmen'+'t'='AUGMENT'
(Other definitions for augment that I've seen before include "Swell" , "boost" , "Increase number of" , "Expand" , "Grow - intensify" .)