be | become | remain | keep sth
I think we should try and keep our arrangements fluid at this stage.

extremely, highly, very
It''s a highly fluid situation.

fairly, quite, rather, relatively

excess | amniotic, bodily/body, intravenous | brake, cleaning

drink
Change your diet and drink plenty of fluids.

lose | replace
replacing vital body fluids and salts that are lost when you sweat

retain
Retaining excess fluid could be a problem.