Prove bit of negligence in two companies (7)
I believe the answer is:
confirm
'prove' is the definition.
(thesaurus)
'bit of negligence in two companies' is the wordplay.
'two companies' means two replacements for 'company'.
'bit of' says to take the initial letters.
'in' indicates putting letters inside.
'company' becomes 'co' (abbreviation).
'company' becomes 'firm' (firm can mean a company or business).
The first letter of 'negligence' is 'n'.
'co'+'firm'='cofirm'
'n' placed into 'cofirm' is 'CONFIRM'.
(Other definitions for confirm that I've seen before include "Ratify; establish" , "Provide support for the truth" , "Philosophy of life" , "Ratify or verify" , "Establish the truth of" .)