Synonyms for Concern:

n.

acquisition, agency, account, anchor, the biz, base, blue-chip, big business, agent, affiliate. apply, compulsion, accountability, obligation, trust, onus, responsibility, relevant, duty, commitment. take effect, cark, interact, make a difference, shape, put, ail, get, bring out, come into play, distress. ardor, love, romance, devotion, deference, admiration, respect, passion. element, feature, basis, key, core, essence, burning issue/question, priority, staple. tension, pressure, strain, alarm, stress. bogey, bugbear, demons, bugaboo, bogie, blanket, canker, cancer. be associated with, be bound up/together, correspond, do with, pertain to, have something to do with something, surround. weigh on, frighten, tear apart, bother, unsettle. affair (noun)
matter.
affection (noun)
love.
attention (noun)
attentiveness, attention, alertness, consideration, concentration, mindfulness, enrapture, notice, caution, regardfulness, interest, care, absorption, diligence, heedfulness, intentness, observation, scrutiny, engrossment, watchfulness, immersion, entrancement, rapture, fascination.
business (noun)
calling, job, firm, position, retailing, establishment, transaction, occupation, busy work, career, negotiation, livelihood, specialty, assignment, profession, situation, merchant, market, proprietorship, business, company, posting, corporation, practice, industry, service, trade, employment, venture, management, consortium, commerce, vocation, labor, station, barter, activity, exchange, affair, selling, holding, enterprise, commission, partnership.
business, responsibility (noun)
interest, job, establishment, transaction, worry, firm, occupation, care, company, matter, corporation, enterprise, affair.
business concern (noun)
company.
concern (noun)
business concern, vexation, Business Organisation, touch, relate, bear on, care, touch on, occupy, refer, business, pertain, come to, fear, business organization, headache, worry.
feeling (noun)
fear, care.
importance (noun)
priority.
interest; anxiety (noun)
attention, consideration, distress, heedfulness.
regard (noun)
mindfulness, attentiveness, care, attention, interest.

v.

affect personally (verb)
bear on, bother, touch, pertain to.
stative (verb)
interest, worry, occupy.

Other synonyms:

ail, bugaboo, accountability, compulsion, basis, cark, responsibility, bugbear, obligation, onus, bogey, weigh on. ardor, element, apply, key, trust, matter, staple, pressure, frighten, blanket. stress, strain. passion. apply
refer.
business organisation
Business Organisation.
pertain
pertain.
touch
be associated with.
Other relevant words:
matter, touch, bear on, distress, respect, worry, bother.

Usage examples for concern

  1. Otherwise feel no concern – Four Arthurian Romances "Erec et Enide", "Cliges", "Yvain", and "Lancelot" by Chretien DeTroyes
  2. It was no concern of mine, but I resented his actions exceedingly. – Captain Macklin by Richard Harding Davis
  3. It didn't concern him. – The Magnetic North by Elizabeth Robins (C. E. Raimond)