Roget's Thesaurus of English Words and Phrases by Peter Mark Roget

120. Synchronism — N. synchronism; coexistence, coincidence;

simultaneousness, simultaneity &c adj.; concurrence, concomitance, unity of time, interim. [Having equal times] isochronism†. contemporary, coetanian†. V. coexist, concur, accompany, go hand in hand, keep pace with; synchronize. Adj. synchronous, synchronal†, synchronic, synchronical, synchronistical†; simultaneous, coexisting, coincident, concomitant, concurrent; coeval, coevous†; contemporary, contemporaneous; coetaneous†; coeternal; isochronous. Adv. at the same time; simultaneously &c adj.; together, in concert, during the same time; in the same breath; pari passu [Lat.]; in the interim; as one. at the very moment &c 113; just as, as soon as; meanwhile &c (while) 106.