D34 may refer to:
*
Akaflieg Darmstadt D-34, a German sailplane
*
BHP Port Kembla D34 class, a class of diesel locomotives
* , a ''Mato Grosso''-class destroyer of the Brazilian Navy
*
D34 road (Croatia)
* , a D-class destroyer of the Royal Navy
* , a V-class destroyer of the Royal Navy
*
LNER Class D34, a class of British steam locomotives
*
Tarrasch Defense
The Tarrasch Defense is a chess opening characterized by the moves:
:1. b:Chess Opening Theory/1. d4, d4 b:Chess Opening Theory/1. d4/1...d5, d5
:2. b:Chess Opening Theory/1. d4/1...d5/2. c4, c4 b:Chess Opening Theory/1. d4/1...d5/2. c4/2...e6, e ...
, a chess opening
* d34, a
die with 34 sides
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