1.
if two people stand back to back , they stand with their backs facing or touching each other
—see also back-to-back
2.
if two or more things happen back to back , they happen one after the other
1.
if two people stand back to back , they stand with their backs facing or touching each other
—see also back-to-back
2.
if two or more things happen back to back , they happen one after the other
Oxford Advanced Learner's English Dictionary. Оксфордский английский словарь для изучающик язык на продвинутом уровне. 2005