Definition of spirantize in US English:

spirantize

(British spirantise)

verb

[with object]Phonetics
  • Pronounce (a consonant) with a continuous expulsion of breath.

    ‘intervocalic voiced stops are generally spirantized’

Origin

Early 20th century: from spirant + -ize.

Pronunciation

spirantize

/ˈspīrənˌtīz//ˈspaɪrənˌtaɪz/