In player parlance, it's
a pushy technique used in making conversation with women where you ask an
open-ended question and stubbornly wait for an answer. You don't say anything until she does, no matter what. You don't fidget, you don't laugh, you don't look apologetic or at all uncomfortable. Eventually, she will get uncomfortable with
the vacuum, and fill it by answering your question, getting herself involved in the conversation.
(You're talking some
woman up, and the convo runs a bit dry, so you turn on
the vacuum:)
You: "Tell me about the best photograph you've ever seen."
Her: Huh?
You: ...
Her: ... (fidgeting)
You: ...
Her: Well, I saw one in a magazine once.
You: ... (cock an eyebrow)
Her: Well, I was flying home from Singapore and there was an article about Cambodia, and I was
kinda bored, but then I turned to the second page and there was this woman staring back at me with the most incredible eyes, I had to stop myself from crying...