流 - current, a sink, flow

elegance; taste; refinement

exchange (e.g. cultural); interchange; interaction; mingling; mixing; coming together

tributary; branch

electric current

inflow; influx

pyroclastic flow

mountain stream; mountain torrent

source (e.g. of a river); headwaters

upper stream; upper course; upper reaches

muddy stream

school (of painting, ikebana, etc.)

second-rate; inferior