Humorist's excursion is usually good for a laugh (5,5)
I believe the answer is:
comic strip
'a laugh' is the definition.
The answer and definition can be both related to communication as well as being singular nouns.
Perhaps you can see an association between them that I can't see?
'humorist's excursion is usually' is the wordplay.
I cannot really see how this works, but
'excursion' could be 'trip' (a trip is an excursion or outing) and 'trip' is found in the answer.
'humorist' could be 'comic' (I've seen this in another clue) and 'comic' is located in the answer.
A single letter 's' remains which might be clued in a way I don't understand.
This explanation may well be incorrect...
'good for' acts as a link.
Can you help me to learn more?
(Other definitions for comic strip that I've seen before include "Sequence of drawings in boxes (telling story)" , "Graphic account" , "Graphic story" , "feature for newspaper" , "Cartoon story" .)