hyperfine

adj

Etymology: Etymology tree Proto-Indo-European *úp Proto-Indo-European *-er Proto-Indo-European *upér Proto-Hellenic *hupér Ancient Greek ῠ̔πέρ (hŭpér) Ancient Greek ῠ̔περ- (hŭper-)der. English hyper- English fine English hyperfine From hyper- + fine.

1. Extremely fine, especially of the hyperfine structure in the spectra of atoms and molecules.