Clarifying a word or term
Sometimes when a speaker is speaking, not understanding a key word or piece of terminology may make it harder for you to follow what's going on. Here are some phrases you could use to ask the speaker to define or explain a term.
If you didn't hear the word clearly and you sense it was important:
"Sorry, what was that word?"
"Sorry, do you mind writing that on the board?"
If you heard/saw it clearly but want the speaker to explain it:
"Sorry, I'm not familiar with that word."
"Sorry, I'm not familiar with that term." (a term means a piece of technical terminology)
"Do you mind explaining what that means? I'm not familiar with that term."
"Sorry, I don't know that term. Could you explain that?"
"Sorry, what's that mean?" I've never heard that before."
"Sorry, what's a _____?
If you're familiar with the word(s) but not with the way the speaker is using it/them:
"What do you mean by ____?"
for example, "What do you mean by 'productive relations'?"
"Sorry, what are you referring to when you say ______"?
for example, "Sorry, what are you referring to when you say 'the built environment'?"