paddy (n.1) Look up paddy at Dictionary.com
"rice field," 1620s, "rice plant," from Malay padi "rice in the straw." Main modern meaning "ground where rice is growing" (1948) is a shortening of paddy field.
Paddy (n.2) Look up Paddy at Dictionary.com
"Irishman," 1780, slang, from the pet form of the common Irish proper name Patrick (Irish Padraig). It was in use in black slang by 1946 for any "white person." Paddy wagon is 1930, perhaps so called because many police officers were Irish. Paddywhack (1881) originally meant "an Irishman."