Pusillanimous

Pusillanimous \pyoo-suh-LAN-uh-muhs\ , adjective;
1. Lacking in courage and resolution; contemptibly fearful; cowardly

This word dates to the late 14th century and comes from Late Latin pusillanimis ("having little courage"), which is from Latin pusillis + animus ("very weak, little" + "spirit, courage"). Pusillis is the diminutive of pullus, or "young animal".
This adjective form was influenced by the noun form pusillanimity, which also dates to the late 14th century but comes via French pusillanimité. Before that the origins are the same.

Today's word and the first definition were both taken from Dictionary.com's 'Word of the Day' for Monday, March 14
Etymologies come from the Oxford English Dictionary and/or Etymonline.com