assibilate
1. [ verb ] insert a sibilant sound before or after (another sound)
Related terms: sibilate sibilant
2. [ verb ] insert a sibilant sound before or after (another sound)
Related terms: sibilate
3. [ verb ] change into a sibilant
Examples:

"In the syllable /si/, the /s/ sibilates in Japanese"

Related terms: change sibilant
Similar spelling:   assibiliate
  assibilation