LSI

LSI may refer to:

== Science and technology == Large-scale integration, integrated circuits with tens of thousands of transistors Latent semantic indexing, a technique in natural language processing LSI-11, an early large-scale integration computer processor that implemented the DEC PDP-11 instruction set Langelier saturation index, a measure for water's tendency to form scale Linear shift-invariant systems, the discrete equivalent of linear time-invariant systems