DEFINITION of -ac

forms adjectives: pertaining to, located in; As a prefix, a- is a privative (negating) morpheme meaning “without,” “not,” or “lacking” — indicating the absence of a structure, function, or condition. It attaches to Greek-derived roots. When the root begins with a vowel, it typically becomes an- to ease pronunciation. As a suffix, -a serves primarily as a grammatical/nominative ending in Latin and Greek nouns (especially neuter plural Latin forms and feminine singular forms), giving medical terms their standard noun form rather than carrying independent clinical meaning.


ETYMOLOGY of -ac

greek From Greek -akos — an adjectival suffix denoting “of,” “belonging to,” or “pertaining to.” Passed into Latin as -acus and into English via French -ac or directly from Latin/Greek. Closely related to the more common suffix -ic (also from Greek -ikos)


RELATED TERMS to -ac

  • Cardiac — pertaining to the heart

  • Iliac — pertaining to the ilium (relevant in urology for iliac vessel proximity in renal/ureteral surgery)

  • Celiac — pertaining to the abdomen

  • Maniac — pertaining to madness

  • Hypochondriac — pertaining to the hypochondrium

  • -al — parallel adjectival suffix (Latin origin)

  • -ic — parallel adjectival suffix (Greek origin)

  • -ary — parallel adjectival suffix (Latin origin)

  • -ac | pertaining to | located in

  • -al | YES | YES |

  • -an | YES | YES |

  • -ar | YES | YES |

  • -ary | YES | - | place for |

  • -eal | YES | YES |

  • -ean | YES | YES |

  • -etic | YES | - |

  • -ic | YES | - | drug | agent

  • -id | YES | - | condition (of) | state (of)

  • -ile | YES | - | capable of (being) | like

  • -ine | YES | YES |

  • -itic (to inflammation) | - | drug | agent

  • -ive | YES | - |

  • -otic | YES | - |

  • -ous | YES | - | characterized by | full of

  • -tic | YES | - | drug | agent, person



Med roots dictionary Appendix A Prefixes Appendix B Combining Forms Appendix C Suffixes Appendix D Suffix forms