Store silicon in warehouse (7)
I believe the answer is:
deposit
'warehouse' is the definition.
(thesaurus)
'store silicon in' is the wordplay.
'store' becomes 'depot' (synonyms).
'silicon' becomes 'Si' (chemical symbol).
'in' means one lot of letters goes inside another.
'depot' placed around 'si' is 'DEPOSIT'.
(Other definitions for deposit that I've seen before include "Sediment or bank lodgment" , "Posited as down payment" , "fur, possibly" , "Down payment made to secure goods" , "Drop" .)