[cies]

The word "strong" is not well defined in this context. But usually it is used for languages like Haskell, Idris, PureScript and Elm.

Ruby does not do as many automatic casts as JS. In this regard it may be seen as "stronger".

[straight-shoota]

Ruby matches this definition: https://www.wikiwand.com/en/Strong_typing

Crystal has static type checking though.

[sarchertech]

Strong is frequently used incorrectly and as such the meaning has been diluted.

But used the way the OP is using it, strong vs weak is different from static vs dynamic.