What is the origin of the idiom "get a word in edgewise" and when to use it?

The idiom "get a word in edgewise" originated from the notion of inserting a remark or comment into a conversation, even when it seems difficult due to the constant flow of talk from others. The phrase suggests that the speaker is managing to slip their words into the narrow spaces ("edgewise") between the ongoing conversation. It is often used to convey the challenge of contributing to a discussion when others are dominating the conversation with their words.