Definition of phi in English:

phi

noun

  • 1The twenty-first letter of the Greek alphabet (Φ, φ), transliterated as ‘ph.’

    • ‘The second main group puts together the GDAP1 proteins with those of the zeta, phi, omega, lambda, tau, beta, and theta classes, plus a few minor sets of sequences.’
    • ‘To design conserved primers, GST nucleotide and protein sequences from the classes phi, tau, and zeta were obtained from GenBank.’
    • ‘This use of h was first established in Latin, which used ch, ph, and th for the Greek letters chi, phi, and theta.’
    1. 1.1Astronomy
      [followed by Latin genitive]The twenty-first star in a constellation.
      ‘Phi Eridani’

  • 1A plane angle.

  • 2A polar coordinate.

    Often coupled with theta

Pronunciation:

phi

/fī/