be a coward

See: fear
References in classic literature ?
The King of Beasts shouldn't be a coward," said the Scarecrow.
Perhaps," said the Lion thoughtfully, "if I had no heart I should not be a coward.
They really are," said the Lion, "but that doesn't make me any braver, and as long as I know myself to be a coward I shall be unhappy.
Every decent man of our age must be a coward and a slave.
In a brief time span I voted and approved of the concept that getting punched in the head was a bad thing, and that I would be a coward from here on in, and avoid getting punched in the head whenever possible.