Definition of microballoon in English:

microballoon

Pronunciation /ˈmʌɪkrəʊbəˌluːn/

noun

  • 1A man-made hollow microsphere, usually of glass or synthetic resin, especially one of a kind used in bulk to provide insulation or buoyancy.

  • 2Medicine
    A very small balloon catheter; the inflatable part of such a catheter.

Origin

1950s; earliest use found in The Official Gazette. From micro- + balloon.