unsprung

English

Etymology 1

From un- +‎ sprung.

Adjective

unsprung (not comparable)

1. Not sprung.

   an unsprung trap

   the unsprung weight of a vehicle

   • 1947 January and February, “Gas Turbine-Electric Locomotive for G.W.R.”, in Railway Magazine, page 26:

     The locomotive is carried on two six-wheel bogies, the outer axles of each bogie being driven by series type d.c. motors, completely suspended to reduce the unsprung weight to a minimum.

   • 1960 February, “Letters to the Editor”, in Trains Illustrated, page 125:

     Amongst the factors peculiar to electric m.u. traction are the heavy unsprung weight of the motors (generally, the greater the weight, the worse is the riding); […] .

2. Not fitted with springs; lacking springs.
   • 2000, Bob Foster, Birdum or Bust!, Henley Beach, SA: Seaview Press, page 169:

     He had an unsprung trailer for the job[.]

Etymology 2

Verb

unsprung

1. simple past and past participle of unspring