Garland that is left upside down (3)
I believe the answer is:
lei
'garland' is the definition.
('lei' can be a synonym of 'garland')
'that is left upside down' is the wordplay.
'that is' becomes 'ie' ('i.e.' can be a synonym of 'that is'**).
'left' becomes 'l' (common abbreviation).
'upside down' says the letters should be written backwards.
'ie'+'l'='iel'
'iel' backwards is 'LEI'.
(Other definitions for lei that I've seen before include "Garland of flowers in Hawaii" , "ready in Romania" , "Hawaiian garland - Romanian money" , "Hawaiian ring of flowers" , "Hawaiian flower garland" .)