Definition of costic in US English:

costic

adjective

English Regional, United States Regional
  • Affected by or causing constipation; = "costive".

Origin

Late 16th century; earliest use found in New Pleasant & Delightfull Astrology. Apparently an alteration of costive, probably by association with caustic (which is attested in the 16th and 17th centuries in the forms costic, costick); compare forms of costive with medial -au-.

Pronunciation

costic

/ˈkɒstɪk/