soapbox

A carton in which soap is packed.

A temporary platform used while making an impromptu or nonofficial public speech.

To engage in impromptu or nonofficial public speaking, often flamboyantly.

(on (one’s) soapbox) Speaking one’s views passionately or self-importantly.

A crate for packing soap, or, by extension, any inexpensive crude platform raised above the surrounding level to give prominence to the person on it, especially when used for speeches.

A talk about one’s pet topic (or the topic itself), especially when only tangentially relevant to an ongoing discussion.

a soapbox car

To give a speech from (or as if from) a soapbox.

a crate for packing soap

a platform raised above the surrounding level to give prominence to the person on it