Lewis Short
(verb) : ob-sĕcro (op-sĕcro), āvi, ātum, 1 (separate, ob vos sacro, for vos obsecro, Paul. ex Fest. p. 190, Müll.), sacro, qs. to ask on religious grounds (ob sacrum), i. e.
* To beseech, entreat, implore, supplicate, conjure: obsecrare est opem a sacris petere, Paul. ex Fest. p. 183 Müll. (class.; syn.: obtestor, precor, supplico).—With acc. of the pers. or thing: Venus alma, ambae te obsecramus, Nos in custodiam tuam ut recipias,Plaut. Rud. 3, 3, 32: advorsum quam ejus me opsecravisset pater,id. Trin. 1, 2, 139: cum eum oraret atque obsecraret,Cic. Verr. 2, 2, 17, § 42: te obsecrat obtestaturque per senectutem suam,conjures you,id. Quint. 30, 91; id. Sest. 69, 147: cum precibus me obsecraret, Marcell. ap. Cic. Fam. 4, 11, 1: cum multis lacrimis,Cic. Verr. 2, 2, 17, § 42; cf. in the foll.: pro di immortales, obsecro vostram fidem,Plaut. Most. 2, 2, 97; id. Poen. 5, 2, 7; id. Truc. 4, 3, 30; cf. in the foll.
* With a double acc. (of the pers. and thing): itaque te hoc obsecrat, ut,Cic. Quint. 31, 97: hoc te,Ter. Heaut. 4, 1, 32.
* In partic., in colloq. lang., obsecro.
* Absol.: videmus certis precationibus obsecrasse summos magistratus,Plin. 28, 2, 3, § 11: Bassus multis precibus, paene etiam lacrimis obsecrabat, implerem meum tempus,Plin. Ep. 4, 9, 12: pro aliquo,Vulg. Esth. 7, 3; id. Philem. 10.
* As an expression of deprecation, I beseech you, I cry you mercy, for Heaven's sake: tuam fidem obsecro,Plaut. Am. 1, 1, 217: periimus! Obsecro hercle,id. Men. 5, 7, 27: Ph. Prodi, male conciliate. Do. Obsecro, Ter. Eun. 4, 4, 2.
* As a mere polite expression of entreaty, for the most part as an interjection, I beseech you, pray: quid illic, opsecro, tam diu restitisti,Plaut. Most. 3, 2, 100; id. Bacch. 5, 2, 12: dic obsecro hercle serio quod te rogem,id. As. 1, 1, 14; Turp. ap. Non. 132, 15: obsecro, an is est?Ter. Eun. 5, 5, 21: Attica mea, obsecro te, quid agit?Cic. Att. 13, 13, 3; id. Tusc. 1, 25, 60: sed obsecro te, ita venusta habeantur ista, non ut vincula virorum sint, sed, etc.,but I beseech you,id. Par. 5, 2, 38; Liv. 5, 6, 3; 6, 40, 10; Gell. 20, 1, 36.
Charlton T. Lewis, Charles Short, A Latin Dictionary