effective >> /əˈfɛktɪv/
Definition: [noun] A soldier fit and available for service.
Example: when the battles broke out, he had a total of 920 effectives
Definition: [adjective] Successful in producing a desired or intended result.
Example: effective solutions to environmental problems
Definition: [adjective] Fulfilling a specified function in fact, though not formally acknowledged as such.
Example: the region did not come under effective Dutch control until 1904