A member of the Conservative Party of Canada.
A personal computer, especially one similar to an IBM PC that runs Microsoft Windows (or, originally, DOS), usually as opposed to (say) an Apple Mac.
forty-nine (an allusion to a cartoon character, Police Constable 49)
To make politically correct.
A large, powerful computer able to manage very many simultaneous tasks and communicate with very many connected terminals; used by large, complex organizations (such as banks and supermarkets) where continuously sustained operation is vital.