talking while standing; standing around talking
隣の人と立ち話をした。
I had a brief chat with my neighbor while standing.
廊下で立ち話をして、すぐに別れた。
We had a quick standing chat in the hallway and then parted ways immediately.
スーパーで偶然会った友人と長い立ち話になった。
I ended up having a long standing conversation with a friend I ran into at the supermarket.