Green’s Dictionary of Slang

sickie n.1

[SE sickleave]

(Aus.) a day’s sick leave; note prison use at cite 1999.

[Aus]T.A.G. Hungerford Riverslake 10: The Pole had been working the plate machine on relief for the regular plate man who was having a sickie.
[Aus]A. Buzo Front Room Boys Scene ii: I took a sickie last year on a bright sunny autumn day.
[Aus]D. Ireland Glass Canoe (1982) 12: He worked for the council for the basic wage and took sickies on Mondays and Fridays.
[Aus]Aus. Women’s Wkly 30 Dec. 130: Even those who went to work would have times when they were home on a ‘sickie’.
[Aus]R.G. Barratt ‘The Isn’t Union Bashing, But’ in What Do You Reckon (1997) [ebook] [I]s there one worker in Australia who hasn’t rorted a sickie?
[UK]C. Newland Scholar 64: ‘How’d you get out of it?’ ‘Took a sickie innit,’ she laughed.
[NZ]D. Looser ‘Boob Jargon’ in NZEJ 13 35: sickie n. To have a -; confinement to cell for medical reasons.
[UK] Advert for lastminute.com in Guardian 2 Aug. 11: Feel a sickie coming on? Book today, go tomorrow [...] Amazing holiday deals.
[Scot]L. McIlvanney All the Colours 13: Did your guys take a collective sickie? Was there an outbreak of salmonella.

In phrases

throw a sickie (v.) (also chuck a sickie, pull a sickie)

to take the day off sick, to pose as ill, esp. when one is perfectly healthy.

[UK]Guardian Jobs 11 Jan. 18/1: Better educated or more senior employees are less likely to throw a sickie.
[Aus]P. Doyle (con. late 1950s) Amaze Your Friends (2019) 124: [Transferred] without warning, so you had no time to stage a sickie or any other trick.
[UK]Indep. on Sun. Real Life 15 Aug. 8: Remember the times you pulled a sickie from school.
[NZ]McGill Reed Dict. of N.Z. Sl. 189: sickie: A day off work, maybe sick, maybe not, almost certainly the latter when a test match is on and large numbers of mostly male staff take/throw a sickie. ANZ mid C20.
[US]T. Jones [bk title] The Little Book of Throwing a Sickie.
[Aus]K.F. Bartolo in Pragmatics & Intercultural Comms 13: Chuck a sickie and jump in the ute.
[UK]D. MacShane Prison Diaries 360: One [screw] tells him to throw a sickie as you can buy time by pretending to be ill.
[Aus]G. Gilmore Class Act [ebook] He managed to surf most days [...] chucking an easy sickie on days like today.