1. coexistent, concurrent, simultaneous. Contemporary,contemporaneous,coeval,coincident all mean happening or existing at the same time. Contemporary often refers to persons or their acts or achievements: Hemingway and Fitzgerald, though contemporary, shared few values.Contemporaneous is applied chiefly to events: the rise of industrialism, contemporaneous with the spread of steam power.Coeval refers either to very long periods of time—an era or an eon—or to remote or long ago times: coeval stars, shining for millenia with equal brilliance; coeval with the dawning of civilization.Coincident means occurring at the same time but without causal or other relationships: prohibition, coincident with the beginning of the 1920s.
British Dictionary definitions for contemporariness
belonging to the same age; living or occurring in the same period of time
existing or occurring at the present time
conforming to modern or current ideas in style, fashion, design, etc
having approximately the same age as one another
noun (pl) -raries
a person living at the same time or of approximately the same age as another
something that is contemporary
(journalism) a rival newspaper
contemporarily, adverb contemporariness, noun
Since contemporary can mean either of the same period or of the present period, it is best to avoid this word where ambiguity might arise, as in a production of Othello in contemporary dress. Modern dress or Elizabethan dress should be used in this example to avoid ambiguity
C17: from Medieval Latin contemporārius, from Latin com- together + temporārius relating to time, from tempus time
1630s, from Medieval Latin contemporarius, from Latin com- "with" (see com-) + temporarius "of time," from tempus "time" (see temporal (v.)). Meaning "modern, characteristic of the present" is from 1866.
"one who lives at the same time as another," 1630s, originally cotemporary, from co- + temporary; modified by influence of contemporary (adj.). Replacing native time-fellow (1570s).