midstream
n[U]
1 part of a stream, river, etc half-way between its banks 中流
There's a fast current in midstream. 中流的水很急.
2 (idm 習語) change/swap horses in midstream => horse. in midstream in the middle of an action, etc 在進行中
The speaker stopped in midstream, coughed, then started up again. 演講人中途停下來咳嗽, 然後又繼續講.