Green’s Dictionary of Slang

1. a red nose.

1909

(ref. to 1882) J. Ware Passing Eng. of the Victorian Era.

2. the head.

1890		C.D. Hickham ‘On His Geranium’ 🎵 His parachute went wrong – oh my, And down he came ker-whop. On his geranium.
1895		Ludlow Advertiser 2 Feb. 7/1: The comic songs, ‘On his geranium’ and [...] ‘He’s got on, Mr Haynes’, lacked nothing in boisterous fun.

3. (US, Western) a person, a fellow.

1906

A. Adams ‘Around the Spade Wagon’ Cattle Brands 🌐 Some geranium out there wants me to come out and shake hands, pow-wow, and make some medicine with him.

4. (US) in pl., cabbage.

1925

J. Stevens ‘Logger Talk’ AS I:3 137/2: Cabbage is ‘geraniums’.