Etymology: < Old French serre, verbal noun < serre-r to hold fast, shut < popular Latin serrāre , altered form of late Latin serāre , < sera bolt, bar. Compare sear n.¹

Etymology: < Latin serĕre to join in a series.

Etymology: Old English séar corresponds to Middle Low German sôr (Low German soor), Dutch zoor < Germanic *sauzo- < Indogermanic *sausó-, whence Lithuanian saũsas, Old Church Slavonic suχŭ, Greek αὖος dry, Sanskrit çōsha drying up, withering. Old English seems to have had also a synonymous derivative síere ( < *sauzjo-), which in later English would be represented by the same form as séar. Earlier currency of the compound Sere-month (as a name for June rather than August) is perhaps implied by G. Hickes's record of the Old English month names (perhaps relying on a lost manuscript):1703 G. Hickes Thesaurus I. 215 (table) Junius... Sere-monað. Mid-su[m]or-monaþ, Ærra liþa, Iunius monaþ.Although it is included in Bosworth-Toller and later dictionaries of Old English, the word is apparently not attested in any extant manuscript from the Old English period.

Etymology: < Old Norse sér, originally dative of the reflexive pronoun (accusative sik, genitive sín); the sense ‘for oneself’ gave rise in Old Norse to the adverbial meaning ‘separately, apart’ (also in compounds, e.g. sérdeilis partly, sérligr particular); the further development into an adjective is peculiar to English. Compare Danish sær singular, Danish især, Swedish sär particularly.