Trumpet has a little weight when picked up (8)
I believe the answer is:
announce
'trumpet' is the definition.
(trumpet can mean to announce or proclaim)
'a little weight when picked up' is the wordplay.
I cannot quite see how this works, but
'a' could be 'an' and 'an' is found within the answer.
'weight' could be 'ounce' (ounce is a kind of weight) and 'ounce' is found in the answer.
A single letter 'n' remains which might be clued in a way I don't understand.
This may be the basis of clue (or it may be nonsense).
'has' is the link.
(Other definitions for announce that I've seen before include "Make known, declare" , "Declare, proclaim" , "Give public notice to" , "Make known officially" , "say" .)