In a listless, languid manner; without interest. .
Lackadaisical may now be a single word but, in its original form, it derived from a phrase, albeit by a circuitous route. The phrase in question is 'alack a day' or 'alack the day'. It was used first by Shakespeare in Romeo and Juliet, 1592, on Romeo's mistaken belief that Juliet had died:
Shee's dead, deceast, shee's dead: alacke the day!
Alack itself can be broken down into the exclamation 'Ah' and 'lack', which then meant failure or shame. Alack-a-day was a recognition of woe or regret at some unfortunate occurrence.
'Alack-a-day' migrated into 'lack-a-day', by a process known as aphesis. This is defined by the OED as - the gradual and unintentional loss of a short unaccented vowel at the beginning of a word; as in squire for esquire.
It was used by John Eachard in The Grounds & Occasions of the Contempt of the Clergy and Religion Enquired, 1685. At that date the 'lack' spelling wasn't yet fully accepted and this citation proceeded the phrases by a hyphen, indicating the missing 'A'.
'Lack a day. how easie a matter is it for old folks to dote and slaver, and for young ones to. be deceived.
Having been shortened 'lack-a-day' now became extended to become the rather fanciful 'lack-a-daisy'. This ornamentation may have been influenced by the existence of the term 'ups-a-daisy', a version of which was in use by 1711.
Tobias Smollett, recorded this piece of street slang in the satirical novel The adventures of Roderick Random, 1748:
Finding the sheets cold, [she] exclaimed, "Good lack-a-daisy! the rogue is fled!"
The novelist Laurence Sterne formed the adjectival form of 'lack-a-daisy', in A Sentimental Journey through France and Italy, 1768:
Would to Heaven! my dear Eugenius, thou hadst passed by, and beheld me sitting in my black coat, and in my lack-adaysical manner.
Lackadaisical may be a single word but it displays an almost Germanic effort to encapsulate an entire paragraph's worth of meaning. To translate from the constituent parts that it is built from, it means 'in the manner of someone who, for all of the day, exhibits a sense of languid dissatisfaction of some failure or fault'.