Analogues are drugs that have close structural resemblance and similar effects. For instance one could argue that naproxen (Aleve) is an analog of ibuprofen (Motrin/Advil). Most analogues are designed because true synthetic natural products are hard to make, or are not potent enough.
Definition of several. 1a : separate or distinct from one another federal union of the several statesb (1) : individually owned or controlled : exclusive a several fishery â compare common (2) : of or relating separately to each individual involved a several judgmentc : being separate and distinctive : respective specialists in their several fields.
An entity is something that exists in itself, actually or potentially, concretely or abstractly, physically or not. It need not be of material existence. In particular, abstractions and legal fictions are usually regarded as entities. In general, there is also no presumption that an entity is animate. The word may refer, for example, to Bucephalus, the horse of Alexander; to a stone; to a cardinal number; to a language; or to ghosts or other spirits. The word entitative is the adjective form of the noun entity. Something that is entitative is considered in its own right.