Shown up by a space traveller (7)
I believe the answer is:
moonlit
'shown' is the definition.
The answer and definition are not the same part of speech. However, past participle verbs and adjectives can sometimes define each other.
'up by a space traveller' is the wordplay.
'up' becomes 'lit' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'by' says to put letters next to each other.
'a space traveller' becomes 'moon' (I've seen this before).
'lit' after 'moon' is 'MOONLIT'.
Can you help me to learn more?
(Other definitions for moonlit that I've seen before include "Illuminated by night" , "Gently illuminated" , "like Titania's unlucky meeting" , "Tom lion (anag)" , "like the bank Jessica used?" .)