BY AND BY.In AV [Note: Authorized Version.] by and by means immediately, not as now after some time. Thus Luk_21:8 the end is not by and by (RV [Note: Revised Version.] immediately).
Hastings' Dictionary of the Bible
Edited by James Hastings, D.D. Published in 1909
In the sense of ?immediately? is the King James Version translation of ἐξαυτῆς, exautḗs, of Mar_6:25 (the American Standard Revised Version ?forthwith?); of εὐθύς, euthús, Mat_13:21 (the American Standard Revised Version ?straightway?); of εὐθέως, euthéōs, Luk_17:7 (the American Standard Revised Version ?straightway?); Luk_21:9 (the American Standard Revised Version ?immediately?). In English literally this meaning is obsolete (compare: ?After you have dyned and supte, laboure not by and by after, but make a pause - the space of an howre or more with some pastyme? (Babees Book, EETS, 247).
International Standard Bible Encyclopedia
PRINTER 1915.