1. With regard or relation to; on the subject of
   "I have a query concerning your previous reply";
   - regarding, about, respecting, re, apropos, as regards, with regard to, as for, as to, in connection with

1. Causing distress, worry or anxiety
   "concerning news";
   - distressing, distressful, disturbing, perturbing, troubling, worrisome, worrying, unsettling

1. Be relevant to
   "These issues directly concern our future";
   - refer, pertain, relate, bear on, touch, touch on, have to do with
    
2. Be on the mind of
   "The upcoming exam concerned all the students";
   - interest, occupy, worry
    
3. Involve oneself or intervene
   "Don't concern yourself with my problems"

See also: heavy

Type of: cerebrate, cogitate, think

Encyclopedia: Concern