Be effusive when taking us in (4)
I believe the answer is:
gush
'be effusive' is the definition.
(I've seen this before)
'taking us in' is the wordplay.
I cannot quite see how this works, but
'us' is within the answer.
This may be the basis of clue (or it may be nonsense).
'when' is the link.
Can you help me to learn more?
(Other definitions for gush that I've seen before include "Sudden stream or jet" , "Spout powerfully" , "Spout like geyser" , "Speak effusively" , "Be over-effusive" .)