A jigger, jowler and back crack; MY CITY.
WHY Liverpool would have a number of names for the alleyways that run behind houses is another one of those mysteries of the city's language. But there are more than a few, including 'back crack', 'entry', 'cooee', 'eenog', 'jigger' and 'jowler.'.
'Entry' is an early 19th century extension of an earlier (16th century) meaning: 'approach to a house'. The shift to the sense of alleyway at the back of a house may well derive from the predominantly working-class habit of only using the back door. 'Eenog' (late 20th century), is probably a derivation from 'entry' (though it's unclear how).
'Back crack' is easier to trace and comes from the 19th century meaning of 'crack' - 'small opening between a door and door-post' (hence 'Ye Cracke', the pub on Rice Street).
'Cooee', on the other hand, which can mean any out of the way place as well as alleyway, is another mystery. It seems to have no connection with 'cooee', used as a call or signal.
'Jowler' and 'jigger' both date to the early 20th century, possibly earlier. It has been argued, possibly speculatively, that the words were used to refer to different sizes of alleyway between back-to-back houses ('jowler' referring to the smaller version). The derivation of 'jowler' is unclear, though one explanation is by derivation from the phrase 'cheek by jowl.' '.' 'Jigger', still used in some areas, is traceable to a 16th century cant term, 'gygger', meaning 'door', which in turn derived from the Welsh 'gwddor', 'gate.'.
Given the creativity of Liverpool English, it is unsurprising that a few of these terms were extended.
'Up the cooee' meant 'in an embarrassing position', while 'jigger rabbit' and 'jowler yowler' meant 'stray cat.'.
TONY CROWLEY AUTHOR OF THE LIVERPOOL-ENGLISH DICTIONARY