concomitant(n = noun.event) accompaniment, attendant, co-occurrence - an event or situation that happens at the same time as or in connection with another;
is a kind of happening, natural event, occurrence, occurrent
has particulars: associate, background

   concomitant(s = adj.all) accompanying, attendant, consequent, ensuant, incidental, resultant, sequent - following or accompanying as a consequence; "an excessive growth of bureaucracy, with attendant problems"; "snags incidental to the changeover in management"; "attendant circumstances"; "the period of tension and consequent need for military preparedness"; "the ensuant response to his appeal"; "the resultant savings were considerable"
Derived form noun concomitance₁

   Accompanying; conjoined; attending. [1913 Webster]
"It has pleased our wise Creator to annex to several objects, as also to several of our thoughts, a concomitant pleasure." [1913 Webster]

   One who, or that which, accompanies, or is collaterally connected with another; a companion; an associate; an accompaniment. [1913 Webster]
"Reproach is a concomitant to greatness." [1913 Webster]
"The other concomitant of ingratitude is hardheartedness." [1913 Webster]

concomitant, adj. & n.
--adj. going together; associated (concomitant circumstances).
--n. an accompanying thing.

Derivative:
concomitantly adv.

Etymology:
LL concomitari (as com-, comitari f. L comes -mitis companion)

N  accompaniment, adjunct, context, appendage, appurtenance, coexistence, concomitance, company, association, companionship, partnership, copartnership, coefficiency, concomitant, accessory, coefficient, companion, buddy, attendant, fellow, associate, friend, colleague, consort, spouse, mate, partner, co-partner, satellite, hanger on, fellow-traveller, shadow, escort, cortege, attribute, accompanying, concomitant, fellow, twin, joint, associated with, coupled with, accessory, attendant, obbligato, with, withal, together with, along with, in company with, hand in hand, side by side, cheek by jowl, cheek by jole, arm in arm, therewith, herewith, and, together, in a body, collectively, noscitur a sociis, virtutis fortuna comes, accompaniment, adjunct, context, appendage, appurtenance, coexistence, concomitance, company, association, companionship, partnership, copartnership, coefficiency, concomitant, accessory, coefficient, companion, buddy, attendant, fellow, associate, friend, colleague, consort, spouse, mate, partner, co-partner, satellite, hanger on, fellow-traveller, shadow, escort, cortege, attribute, accompanying, concomitant, fellow, twin, joint, associated with, coupled with, accessory, attendant, obbligato, with, withal, together with, along with, in company with, hand in hand, side by side, cheek by jowl, cheek by jole, arm in arm, therewith, herewith, and, together, in a body, collectively, noscitur a sociis, virtutis fortuna comes.

N  synchronism, coexistence, coincidence, simultaneousness, simultaneity, concurrence, concomitance, unity of time, interim, isochronism, contemporary, coetanian, synchronous, synchronal, synchronic, synchronical, synchronistical, simultaneous, coexisting, coincident, concomitant, concurrent, coeval, coevous, contemporary, contemporaneous, coetaneous, coeternal, isochronous, at the same time, simultaneously, together, in concert, during the same time, in the same breath, pari passu, in the interim, as one, at the very moment, just as, as soon as, meanwhile.