Check the others have water (8)
I believe the answer is:
restrain
'check' is the definition.
(I know that check is a more specific form of the action restrain)
'others have water' is the wordplay.
'others' becomes 'rest' (eg the rest of a group).
'have' says to put letters next to each other.
'water' becomes 'rain' (rain is a kind of water).
'rest'+'rain'='RESTRAIN'
'the' is the link.
(Other definitions for restrain that I've seen before include "bottle up" , "Prevent (from excess)" , "use handcuffs?" , "stay" , "bar" .)