Meaning of BACKWARD in English
1》 directed behind or to the rear.
2》 having made less progress than is normal or expected.
↘(of a person) having learning difficulties.
3》 [with negative ] ( ~ in ) lacking the confidence to do: he was not ~ in displaying his talents.
4》 Cricket (of a fielding position) behind an imaginary line passing through the stumps at the batsman's end at right angles to the wicket.
■ adverb variant of ~s .
ME: from earlier a~ , from aback .
Concise Oxford English vocab. Сжатый оксфордский словарь английского языка. 2004