Embed Mike into one factory (7)
I believe the answer is:
implant
'embed' is the definition.
(I know that embed can be written as implant)
'mike into one factory' is the wordplay.
'mike' becomes 'M' (phonetic alphabet: alpha, bravo, charlie etc.).
'into' means one lot of letters goes inside another.
'one' becomes 'i' (Roman numeral).
'factory' becomes 'plant' (I've seen this before).
'i'+'plant'='iplant'
'm' put into 'iplant' is 'IMPLANT'.
(Other definitions for implant that I've seen before include "Something surgically grafted into body" , "Introduce" , "Fix firmly" , "Graft into the body" , "Inculcate; embed" .)