τό, indecl., the Hebrew Passover (from pāsaḥ ΄pass over΄) or Paschal feast, LXX Ex. 12.48, etc.
paschal supper, Ev. Matt. 26.17, 19, al.
paschal lamb, θύειν τὸ π. LXX Ex. 12.21, al. ; τὸ π. ἐτύθη Χριστός 1 Ep. Cor. 5.7.

πάσχα, τό indecl. (Aram. טַּסְחָא),
[in LXX for פֶּסַח ;]
__1. the festival of the Passover: Mat.26:2, Mrk.14:1, Luk.22:1, Jhn.2:13, 23 6:4 11:55 12:1 18:39 19:14, Act.12:4, Heb.11:28; .ἡ ἐορτὴ τοῦ π., Luk.2:41, Jhn.13:1.
__2. By meton.,
__(a) the paschal supper: ἑτοιμάζειν τὸ π., Mat.26:19, Mrk.14:16, Luk.22:8, 13; ποιεῖν τό π., Mat.26:18;
__(b) the pasohal lamb: θύειν τό π. (Exo.12:21), Mrk.14:12, Luk.22:7; of Christ, 1Co.5:7; φαγεῖν τὸ π. (lamb or supper), Mat.26:17, Mrk.14:12, 14, Luk.22:11, 15, Jhn.18:28 (cf. 2Ch.30:17).†
(AS)