A metrical foot of with a strong stress followed by a weak, as in the following example from Louis MacNeice's 'Postcript to Ireland”: “Still I drink your helath before / The four butt raps upon the door”.
Editors. "Trochee (Trochaic)". The Literary Encyclopedia. First published 01 November 2001
[http://www.litencyc.com/php/stopics.php?rec=true&UID=1143, accessed 30 July 2014.]