A small platter is out of place (6)
I believe the answer is:
astray
'out of place' is the definition.
(both can mean lost)
'a small platter' is the wordplay.
'small' becomes 's' (abbreviation - e.g. clothes size).
'platter' becomes 'tray' (tray for food).
'a'+'s'+'tray'='ASTRAY'
'is' acts as a link.
(Other definitions for astray that I've seen before include "Off target" , "on the wrong road" , "Wandering, errant" , "Go . . . . . . - get lost" , "Off the correct path" .)