Definition of medigap in US English:

medigap

noun

US
  • Any of various limited forms of U.S. private health insurance which pays for medical services additional to those covered by the government health insurance plans. Usually attributive.

Origin

1960s; earliest use found in The Oakland Tribune. From medi- + gap, after Medicare.

Pronunciation

medigap

/ˈmɛdɪɡap/