Green’s Dictionary of Slang

1. (US) an infantryman.

1948		Lay & Bartlett Twelve O’clock High! (1975) 322: None of us paddle-feet would have gone along with you today if we’d thought it was dangerous!
1950		Life 2 Jan. 98/2 Murray was a paddlefoot in Europe.
1960, 1975		Wentworth & Flexner DAS 372/1: Paddlefoot [...], an infantry soldier.
2000		(ref. to WWII) Online Etymology Dict. 🌐 paddlefoot, World War II U.S. Army slang for ‘infantry soldier.’.

2. attrib. use of sense 1.

1957		New Yorker 23 Nov. 67/3 A paddlefoot mess officer in North Africa.
1944		H.B. Hersey G.I. Laughs 35: Announcing ‘The Paddlefoot Zoot Suit’.