If by dynamic, you mean: the compiled code for the same exact shader source code can be wildly different at runtime, based on the inputs, OSL is dynamic in that sense.
If you mean something else…then I guess not. It's a shader after all, not a general purpose programming language.
I tend to use dynamic in the sense of static vs. dynamic, where dynamic is "happens at runtime" and static is "happens before runtime".
I think nadav256 meant dynamically typed. I.E. most languages that target LLVM are statically typed, and this project is one of the few (the first?) to successfully leverage LLVM for a dynamically typed language.
Julia is another dynamically typed language using LLVM. On the other hand, Julia was designed to use LLVM. I think this may be the first to succeed in dynamically typed language not designed to use LLVM.
If you mean something else…then I guess not. It's a shader after all, not a general purpose programming language.
I tend to use dynamic in the sense of static vs. dynamic, where dynamic is "happens at runtime" and static is "happens before runtime".