Green’s Dictionary of Slang

bumper n.4

[butt n.1 (2) + SE stump]

(Aus./N.Z.) a cigarette butt; thus bumper-hunter n., one who picks up cigarette butts from the street.

[Aus]Dead Bird (Sydney) 21 June 2/4: ‘And the young imp begged a bumper and strolled off’.
[Aus]Aus. Tit-Bits (Sydney) 6 May 194/3: Bumper hunters [...] are men and boys who, unable to buy tobacco, or in order to save money, make a practice of picking up and smoking all the ‘butts’ [...] of cigars and cigarettes which they can find lying in the streets [AND].
[Aus]Stephens & O’Brien Materials for a Dict. of Aus. Sl. [unpub. ms.] 31: BUMPER: Sydney slang: a cigarette or cigar stump or butt.
[Aus]Bulletin (Sydney) 30 July 14/2: ‘Ow’d y’ come t’ git th’ shove?’ ‘Through not clingin’ t’ th’ all-powerful, Mucker,’ answered Ponto, gloomily, and ‘waxed’ the end of an unhealthy-looking bumper, preparatory to lighting it.
[Aus]C.E.W. Bean Anzac Book 47/2: One mornin’ early while we was standin’ to arms ’e lights up a bumper, so I tells ’im not to let the officer cop ’im or there’d be trouble.
[UK](con. WWI) E. Lynch Somme Mud 34: The poor upturned hand is half full of cigarette bumpers.
[US]A.J. Pollock Und. Speaks.
[Aus]Lachlander and Condobolin Recorder (NSW) 4 Jan. 3/4: I watched this country boarder / On the floor with cushion underneath his knees / Picking bumpers off the carpet.
[Aus]K. Tennant Joyful Condemned 244: Got any cigarettes [...] Harry’s good for a bumper sometimes.
[Aus]F.J. Hardy in Great Aus. Lover Stories 35: What did he find in his pocket? —A dirty old bumper, a cigarette butt.
[Aus] ‘Whisper All Aussie Dictionary’ in Kings Cross Whisper (Sydney) xxxiv 4/3: dog end: English for bumper, fag end, doughey, Victor Trumper.
[Aus]D. O’Grady Bottle of Sandwiches 30: Hope he brings the makin’s we asked him to. Smokin’ bumpers is all right when there’s nothin’ else, but by tomorrow we’ll be bumperin’ the bumpers.
[Aus]R. Beckett Dinkum Aussie Dict. 12: Bumper: A cigarette butt.
(con. WWII) The 42nd Australian Infantry Battalion in World War 2 ‘Digger Sl.’ [Internet] Bumper sniping — cleaning up (including or especially cigarette ends, called bumpers).

In compounds

bumper-shooter (n.) [SE shooter; note Aus. army sl. bumper-sniping, a punishment that requires the defaulter to pick up cigarette-ends]

(Aus.) a picker-up of discarded cigarette ends; thus bumper-shooting, bumper-dashing, bumper-sniping, following this practice.

[Aus]Stephens & O’Brien Materials for a Dict. of Aus. Sl. [unpub. ms.] 31: Bumper shooters are the loafers who pick up these bumpers [i.e. cigarette/cigar ends] to smoke.
[Aus]Baker Aus. Lang. 107: Bumper-sniping or bumper-dashing, the picking up of cigarette butts.
[Aus]Stirling & Richardson Memories of Aberfeldy 24: Shabby figures in the shameful dull black shuffling along Collins Street [...] ‘bumper shooting’ (picking up discarded cigarette butts) [AND].
(con. WWII) The 42nd Australian Infantry Battalion in World War 2 ‘Digger Sl.’ [Internet] Bumper sniping — cleaning up (including or especially cigarette ends, called bumpers).

In phrases

not worth a bumper (adj.)

(Aus.) worthless, useless.

[Aus]L. Glassop Lucky Palmer 28: Sheilas don’t interest me. They’re not worth a bumper.
[Aus]S. Gore Holy Smoke 77: Sand, flies, wait-a-bit thorn, Joe Blakes – the lot, that place; not worth a bumper.
[Aus]D. Ireland Burn 44: Billy, you’re not worth a bumper.
[Aus]R. Beckett Dinkum Aussie Dict. 38: Not worth a bumper [...] Worthless.
[Aus]G. Seal Lingo 127: There are [...] subtle gradations in the types of stupidity, thoughtlessness, hopelessness, incapacity and sheer ineptitude that may come in for verbal censure. A person may be: [...] not worth a bumper.