| Main Entry: | simultaneous |
| Part of Speech: | adjective |
| Definition: | happening at about the same time |
| Synonyms: | accompanying, agreeing, at the same time, coetaneous, coeval, coexistent, coexisting, coincident, coinciding, concurrent, concurring, contemporaneous, contemporary, dead heat, in sync, synchronal, synchronic, synchronous, with the beat |
| Antonyms: | asynchronous, different, divided, following, preceding, separate |
| Main Entry: | coincident |
| Part of Speech: | adjective |
| Definition: | concurring, happening together |
| Synonyms: | ancillary, attendant, attending, coinciding, collateral, concomitant, consonant, contemporaneous, contemporary, coordinate, correspondent, incident, satellite, simultaneous, synchronous |
| Main Entry: | contemporary |
| Part of Speech: | adjective |
| Definition: | existing, occurring at same time |
| Synonyms: | accompanying, associated, attendant, coetaneous, coeval, coexistent, coexisting, coincident, concomitant, concurrent, connected, contemporaneous, current, linked, present, related, simultaneous, synchronal, synchronic, synchronous |
| Notes: | contemporary can be predicated of persons, conditions, or events; contemporaneous is predicable only of occurrences or events |
| Antonyms: | future, past, preceding, succeeding |
| Main Entry: | upon |
| Part of Speech: | preposition |
| Definition: | at the time of |
| Synonyms: | beginning with, consequent to, simultaneous |
| Main Entry: | synchronous |
| Part of Speech: | adjective |
| Definition: | occurring or existing at same time |
| Synonyms: | coexistent, concomitant, concurrent, contemporary, identical, simultaneous |
| Main Entry: | coetaneous |
| Part of Speech: | adjective |
| Definition: | contemporary |
| Synonyms: | coeval, coexistent, coexisting, concomitant, contemporaneous, simultaneous, synchronic, synchronous |
| Main Entry: | coexistent |
| Part of Speech: | adjective |
| Definition: | contemporary |
| Synonyms: | coetaneous, coeval, coexisting, concomitant, contemporaneous, simultaneous, synchronic, synchronous |
| Main Entry: | contemporaneous |
| Part of Speech: | adjective |
| Definition: | contemporary |
| Synonyms: | coetaneous, coeval, coexistent, coexisting, concomitant, simultaneous, synchronic, synchronous |