خفو1 خَفَا, (S, K,) aor. ـْ (S,) inf. n. خَفْوٌ (S, K) and خُفُوٌّ; (ISd, K;) and خَفَى, aor. ـْ inf. n. خًفْىٌ; (S, TA;) and خَفِىَ, aor. ـْ inf. n. خَفْىٌ; (Kr, TA;) said of lightning, It flashed, gleamed, or shone, (S, K, TA,) faintly, extending sideways in the adjacent tracts of cloud: when it flashes, gleams, or shines, a little, and then ceases, not extending sideways, it is termed وَمِيضٌ; and when it cleaves the clouds, and extends high, into the midst of the sky, without going to the right and left, it is termed عَقِيقَةٌ: (S, TA:) accord. to A 'Obeyd, خَفْوٌ signifies the extending of lightning sideways in the tracts of the sky. (TA.) b2:  And خَفَا, (K,) inf. n. خَفْوٌ, (TA,) It (a thing) appeared. (K, TA. [See also خَفِىَ, in art. خفى.]) خِفْوَةٌ i. q. خِفْيَةٌ, (K, TA, [in the CK, erroneously, خَفِيَّة,]) an inf. n. of خَفِيتُ لَهُ as syn. with اِخْتَفَيْتُ, (K * and TA in art. خفى, q. v.,) the و and ى being interchangeable. (TA.)