Jam-packed deliveries left Yemen port (9)
I believe the answer is:
overladen
'jam-packed' is the definition.
(both can mean very full up)
'deliveries left yemen port' is the wordplay.
'deliveries' becomes 'over' (a cricket over consists of six deliveries).
'left' becomes 'L' (common abbreviation).
'yemen port' becomes 'aden' (I've seen this before).
'over'+'l'+'aden'='OVERLADEN'
(Other definitions for overladen that I've seen before include "Evidently stuffed" , "Carrying excessive amount" , "low in the water?" , "Bearing excessive load" , "Groaning" .)