British use of the word rubber

British English uses the word rubber as follows:

1. To refer to the raw material harvested from the juice/sap of rubber trees which are grown in their millions on plantations in Asia. Much of this raw material is processed and manufactured into car tyres (BrE)/car tires (AmE) which, for the most part, are made of rubber. There are many other products, large and small, that are made from rubber;

2. What our American friends call an eraser, we the Brits call a rubber. Generations of school kids have kept a rubber in their pencil cases, ready at hand to rub out (erase) mistakes in spelling that occur when the child is learning to write on paper with a pencil;

3. Is slang and/or a less formal way of referring to a condom. The Durex brand of condom or rubberis the market leader in the UK and is made by the London Rubber Co. Ltd. The use of the word rubber in this context is more common in AmE.

4. The word rubber is used in connection with a series of games or sports. It is also used in card games like Bridge;

5. A rubber spatula is a tool that is commonly used in cooking.

Rubber: "an elastic substance (= that stretches) made either from the juice of particular tropical trees or artificially; UK an eraser; slang for a condom; a series of three or five games between two teams, especially in card games". (Dictionary Cambridge)

Rubber spatula: [used in cooking] "It has a broad, flat and usually flexible rubber blade that is used for blending food or removing it from cooking vessels such as pans, bowls or cans". (www.reference.com)

With regard to the OP’s Tarzan quote, the context is obviously some kind or First Aid treatment in the field administered to someone who has sustained a cut. Tarzan comes to the rescue and suggests a poultice which is to be spread on the cut by means of a rubber spatula.