A big hit; poetry that is fashionable (1,2,4)
I believe the answer is:
a la mode
'is fashionable' is the definition.
(a la mode can mean trendy or fashionable)
'a big hit poetry' is the wordplay.
'big hit' becomes 'lam' (to 'lam' means to hit hard. I am not sure about the 'big' bit.).
'poetry' becomes 'ode' (ode is a type of poem).
'a'+'lam'+'ode'='A LA MODE'
'that' is the link.
Can you help me to learn more?
(Other definitions for a la mode that I've seen before include "In fashion - served with ice cream" , "all the rage" , "In the fashion, in Paris?" , "Fashionable -- served with ice cream" , "Fashionable in France" .)