take it as PUSSY + ANIMAL = a pussy will always be dumb and cowardly, will always lack courage.
pussillanimous --> PUSSY with ANIMUS(enemy). So, someone who behaves like a pussy cat with his enemies is coward and also remember PUISSANT means powerful and strong
if someone is coward,they call him 'pussy,u r no man'
pussy is a silly animal...coz it is cowardly (pussy+silly+animus)...!!!
pusill-petty, very small; anim-spirit. Petty spirit == timid, cowardly.