1
general::
Also, get a word in edgeways. Insert oneself into a conversation or express one's opinion despite competition from other speakers. For example, So many people had questions for the lecturer that it was hard to get a word in edgewise, or Nancy loves to talk, and I couldn't get a word in edgeways. This idiom, often put in the negative, transfers an object with its edge foremost to inserting conversation. [Late 1700s]
American Heritage Idioms
2
general::
Phrase(s): get a word in edgewise [and] get a word in edgeways
Fig. to manage to say something when other people are talking and ignoring you. (Often in the negative. Alludes to trying to "squeeze" a word into a running conversation.) • It was such an exciting conversation that I could hardly get a word in edgewise. • Mary talks so fast that nobody can get a word in edgeways.
McGrawhill's American Idioms And Phrasal Verbs