Orchid seen in deep blue lake in Virginia (7)
I believe the answer is:
vanilla
'orchid' is the definition.
(I know that Vanilla is a type of orchid)
'deep blue lake in virginia' is the wordplay.
'deep blue' becomes 'anil' (blue dye and its specific colour).
'lake' becomes 'L' (geographical abbreviation).
'in' is an insertion indicator.
'virginia' becomes 'va' (US state abbreviation).
'anil'+'l'='anill'
'anill' put into 'va' is 'VANILLA'.
'seen in' acts as a link.
(Other definitions for vanilla that I've seen before include "ice cream, perhaps" , "Pods to flavour, ice-cream, say" , "Ordinary" , "conventional" , "Tasty flavouring for ice-cream" .)