1. With regard or relation to
   "I have a query concerning your previous reply"
   - regarding, respecting, re

1. Be relevant to
   - refer, pertain, relate, come to, bear on, touch, touch on, have to do with 
2. Be on the mind of
   - interest, occupy, worry

Encyclopedia: Concern

• social psychology
• social rank
• social reformer
• social relation
• social science
• social scientist
• social season
• social secretary
• Social Security
• Social Security Administration
• Social Security number
• social service
• social station
• social status
• social stratification
• social structure
• social studies
• social system
• social unit
• social welfare
• social work
• social worker
• socialisation
• socialise
• socialised