The Collaborative International Dictionary
Strengthening plaster
Strengthening \Strength"en*ing\, a. That strengthens; giving or increasing strength. -- Strength"en*ing*ly, adv.
Strengthening plaster (Med.), a plaster containing iron, and supposed to have tonic effects.
Wiktionary
strengthening plaster
n. (context medicine archaic English) A plaster containing iron, supposed to have tonic effects.