Who is the coward of the play in twelve angry men?

I would say Juror #7.

The 7th Juror’s main concern in the case is whether or not it will end before his ball game, for which he has tickets. He sells marmalade and is generally indifferent to the case. He changes his vote to “not guilty” simply because the tide of opinion switches, and he wants the deliberations to be over. He is a bully and a coward, quick to form opinions on little information.