Terms of local area network broken by electronic security breach? (4)
I believe the answer is:
leak
'security breach?' is the definition.
(I've seen this in another clue)
'terms of local area network broken by electronic' is the wordplay.
'terms of' indicates one should take the final letters (term can mean the end of something).
'broken by' is an insertion indicator (inserted letters break into the word).
'electronic' becomes 'e' (as in e-mail or e-books).
The last letters of 'local area network' are 'lak'.
'lak' placed around 'e' is 'LEAK'.
(Other definitions for leak that I've seen before include "Divulge" , "Spill secrets" , "Escape - make (confidential information) known" , "Let in water" , "Reveal (secret)" .)