D defs.my
Entry 1 sense Webster, 1913

Single-acting

· Sin·gle-act·ing · IPA
01 a. Having simplicity of action; especially (Mach.), acting or exerting force during strokes in one direction only; -- said of a reciprocating …
  1. 1.
    Having simplicity of action; especially (Mach.), acting or exerting force during strokes in one direction only; -- said of a reciprocating engine, pump, etc.(Mach.)