Way to communicate in period without company (8)
I believe the answer is:
intercom
'way to communicate' is the definition.
(I've seen this before)
'in period without company' is the wordplay.
'period' becomes 'term' (term is a kind of period).
'without' means one lot of letters goes inside another ('without' can be similar in meaning to 'outside').
'company' becomes 'co' (abbreviation).
'term' enclosing 'co' is 'tercom'.
'in'+'tercom'='INTERCOM'
(Other definitions for intercom that I've seen before include "System of communication by radio or telephone" , "Short-range telephone system" , "Means of transmitting messages" , "Speaker system" , "way to communicate" .)