Word Study
simultaneous
CIDE DICTIONARY
simultaneous, a. [LL. simultim at the same time, fr. L. simul. See Simulate.].
Existing, happening, or done, at the same time; as, simultaneous events. [1913 Webster]
OXFORD DICTIONARY
simultaneous, adj. (often foll. by with) occurring or operating at the same time.
Idiom
simultaneous equations equations involving two or more unknowns that are to have the same values in each equation.
Derivative
simultaneity n. simultaneously adv. simultaneousness n.
Etymology
med.L simultaneus f. L simul at the same time, prob. after instantaneus etc.
THESAURUS
simultaneous
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, unisonousROGET THESAURUS
simultaneous
Synchronism
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.For further exploring for "simultaneous" in Webster Dictionary Online