Poem in secret language Charlie ignored (3)
I believe the answer is:
ode
'poem' is the definition.
(ode is a kind of poem)
'secret language charlie ignored' is the wordplay.
'secret language' becomes 'code' (I've seen this before).
'charlie' becomes 'c' (phonetic alphabet: alpha, bravo, charlie etc.).
'ignored' indicates named letters should be taken away.
'code' with 'c' taken away is 'ODE'.
'in' is the link.
(Other definitions for ode that I've seen before include "Poetic composition" , "(Railway)system" , "poetry" , "Poem in praise of doe" , "Literary work" .)