1.  dosage(n = noun.quantity) dose - the quantity of an active agent (substance or radiation) taken in or absorbed at any one time;
is a kind of indefinite quantity
Derived forms verb dose₂, verb dose₁

2.  dosage(n = noun.artifact) dose - a measured portion of medicine taken at any one time;
is a kind of medicament, medication, medicinal drug, medicine
has particulars: booster, booster dose, booster shot, recall dose, draft, draught, hit, lethal dose, lozenge, pill, tab, tablet

dosage, n.
1 the giving of medicine in doses.
2 the size of a dose.