Green’s Dictionary of Slang

1. a bill; in pl. any form of sign (i.e. a handbill) denoting one’s qualifications for begging (‘blind’, ‘ex-soldier’ etc).

1910		Eve. Teleg. (Dundee) 3 Aug. 4/1: He pays his 'Beecham's pill,' tells the landlady he thinks it is going to 'Corney' (corney grain - rain).
1937–84		Partridge DSUE (1984) 64/1: —1935.
1960		J. Franklyn Dict. of Rhy. Sl. 37/2: Beecham’s Pills (1) Bills [...] refers to the notice stating for example, ‘Ex-service, man – no pension.’ [foll. 1914–18 war].
1969		S.T. Kendall Up the Frog.

2. (Aus., also Beecham’s) a fool, a simpleton [dill n.¹ ].

1952		Argus (Melbourne) 13 June 4s/3: You’d be a bit of a ‘Beecham’s pill’ if you couldn’t work it out.
1967		‘Whisper All Aussie Dict.’ in Kings Cross Whisper (Sydney) xxxii 6/1: beechams: A dope or a dill. Rhyming slang derived from Beechams Pill.
1968		J. Alard He who Shoots Last 95: Yer becomin’ a bigger Beecham’s pill dan yer cousin.
1986		R.G. Barrett Godson 23: ‘You must know someone who can look after this Beecham’s pill’.
1999		G. Seal Lingo 91: Then there are those things that form the basis for still more distinctively Australian rhymes, including: [...] beecham’s pill for dill, usually just beecham’s.
2004		R.G. Barrett Rosa Marie’s Baby (2013) [ebook] ‘I feel like a nice Beecham’s Pill’.

3. a still (photograph).

1984

Partridge DSUE (8th edn) 64/1: since ca. 1950.

4. (also Beecham’s) a will.

1979

F. Norman Too Many Crooks Spoil the Caper 155: The gem belongs to her by rights – her dad left it to her in his Beecham’s.