diff --git a/geometry/grassmann_test.cpp b/geometry/grassmann_test.cpp
index 19453b4fe0..a0016b8465 100644
--- a/geometry/grassmann_test.cpp
+++ b/geometry/grassmann_test.cpp
@@ -69,7 +69,6 @@ class GrassmannTest : public testing::Test {
                       Inertial,
                       Handedness::Right,
                       serialization::Frame::TEST>;
-  Vector<World, Acceleration> γ;
 
   R3Element<Length> const null_displacement_ = {0 * Metre,
                                                 0 * Metre,