| Simultaneous (a.) Existing or happening at the same time; as, simultaneous events. Thesaurus Entries accessory, accompanying, agreeing, associated, attendant, attending, coetaneous, coeternal, coeval, coexistent, coexisting, coincident, coinciding, coinstantaneous, collateral, combined, concomitant, concurrent, concurring, conjoint, contemporaneous, contemporary, conterminous, correlative, coterminous, coupled, fellow, isochronal, isochronous, joined, joint, mutual, paired, parallel, synchronal, synchronic, synchronous, twin, unison, unisonous |