on the left,
is Water.
The top and middle of the right part is something blocking the flow, like dam or stone, the bottom part is the flow.
Its small seal script is
very similar to the big seal script.
Its clerical script is
the left changed to "three drops" radical, which represents that the character is water related. The right part is similar to older scripts.
The current printing script is
流
similar to its clerical script.
Its pinyin is "Liu2".