question

"the researchers used a spectrometer to confirm that the spider in its web is spectrally indistinguishable from bird splat" in this sentence, what's the word "splat"mean?

Correct version:

Question

"The ressearchers used a spectrometer to confirm that the spider in its web is spectrally indistinguishable from bird splat."  In this sentence, what does the word "splat" mean?

Explanation:

Titles are always capitalized in English.

"What" and "does" are not used as a contraction.

To answer your question:

In this case "splat" is referring to the smear of a bird dropping.  "Splat" is usually a word that describes the sound of something wet and soft hitting something hard - like a bird dropping hitting the windshield of a car.