Full Idea
A logically determinate name is one which names the same thing in every possible world.
Gist of Idea
A logically determinate name names the same thing in every possible world
Source
David Lewis (How to Define Theoretical Terms [1970], III)
Book Reference
Lewis,David: 'Philosophical Papers Vol.1' [OUP 1983], p.86
A Reaction
This appears to be rigid designation, before Kripke introduced the new word.