What's the meaning of the phrase 'Dilly-dally'?
To 'dilly-dally' is to be indecisive; vacillating and making no advance.
What's the origin of the phrase 'Dilly-dally'?
The reduplicated expression dilly-dally is one of the rarer form - it is formed by adding an alliterative word in front of the 'meaning' word dally. Most such expressions start with a word with a known meaning and add a rhyming word behind, like easy-peasy or okey-dokey.
The root word here, dally, has been used since the 14th century to mean 'to converse idly; to chat'.
The first example that I know of of it being paired with dilly is found in print in the 1592 collection of notes published by Gervase Babington, the Bishop of Landaph:
Such dilly dally is fitter for Heathens that knowe not God, then for sober Christians.
Over time, dally began to be used with modified meaning. By the 16th century it was used to mean 'To spend time idly or frivolously; to linger, loiter; to delay.'.
That's the meaning behind the lyrics of the nest-known use of dill-dally, the 1919 song made popular by the English music hall performer Marie Lloyd - ^:
My old man said "Follow the van,
And don't dilly dally on the way".
Off went the van with me home packed in it,
I walked behind with me old cock linnet.
But I dillied and dallied, dallied and I dillied
Lost me way and don't know where to roam.
Well you can't trust a special like the old time coppers.
When you can't find your way home.
It seems reasonable to assume that the slightly later expression 'shilly-shally' is just a variant of 'dilly-dally'.
Actually, it isn't. 'Shilly-shally' is formed as an allusion to 'Shall I? Shall I not?' and, as such, has more in common with the even earlier willy-nilly.