Eggs are put face upwards (4)
I believe the answer is:
laid
'eggs are' is the definition.
The definition and answer can be both to do with ownership as well as being past participle verbs.
Perhaps you can see a link between them that I can't see?
'face upwards' is the wordplay.
'face' becomes 'dial' (face of a clock).
'upwards' says the letters should be written backwards.
'dial' back-to-front is 'LAID'.
'put' is the link.
Can you help me to learn more?
(Other definitions for laid that I've seen before include "Produced eggs" , "Placed horizontally on a surface" , "Doze" , "The clutch must be" , "tables may be?" .)