Phenoxymethyl penicillin has 2 different meanings across 1 category:
a crystalline penicillin similar in action to penicillin G but more resistant to the action of gastric acids
A crystalline nonhygroscopic acid that is a semisynthetic form of penicillin, used in the form of its sodium or potassium salt C₁₆H₁₇KN₂O₅S, and has antibacterial action similar to benzylpenicillin and is more resistant to inactivation by gastric acids; 6-phenoxyacetamidopenicillanic acid, C₁₇H₂₀N₂O₆S.