underframe (plural underframes)
- The supporting structure of a piece of furniture, a vehicle, etc.
- 1960 March, “Talking of Trains: S.R. multiple-unit news”, in Trains Illustrated, page 125:
- Nos. 5300/1, which were finished in January, are the Southern's first "4-EPB" units to the standard B.R. design on 63 ft. 5 in. underframes, as against the S.R. 62 ft.; [...].