I caught a bird that's pulled up the lettuce (7)
I believe the answer is:
iceberg
'lettuce' is the definition.
(I know that iceberg is a type of lettuce)
'i caught a bird that's pulled up' is the wordplay.
'caught' becomes 'c' (cricket abbreviation).
'a bird' becomes 'grebe' (type of bird).
'that's pulled up' shows that the letters should be reversed in order.
'grebe' in reverse letter order is 'eberg'.
'i'+'c'+'eberg'='ICEBERG'
'the' is the link.
(Other definitions for iceberg that I've seen before include "Arctic shipping hazard" , "Most of it is below the surface" , "Unlikely feature of Cos" , "that has hidden depths?" , "One destroyed the Titanic" .)