-bundus

From Proto-Indo-European *bʰuH- (“to become, to grow”) (whence also fīō, fuī, futūrus and other verb forms of esse starting with fu-). Perhaps from Proto-Italic *-βuwontnos < syncopated from *-βuwontinos, from the Proto-Indo-European aorist participle *bʰuHónt- + *-(i)nós. The development of the Latin gerundive and later gerund has been traced to analogous derivations from the Proto-Indo-European *-ont- (participial suffix) +‎ *-(i)nós (adjective-forming suffix) in secundus, oriundus, rotundus, and lābundus.^[1] Compare -undus and -cundus.

• (Classical Latin) IPA^(key): /ˈbun.dus/,
• (modern Italianate Ecclesiastical) IPA^(key): /ˈbun.dus/,

-bundus (feminine -bunda, neuter -bundum); first/second-declension suffix

1. Derives adjectives with an active or transitive meaning, sometimes even taking a direct object.^[2]

   ‎cantō (“sing”) + ‎-bundus → ‎cantābundus (“singing”)

   ‎furō (“rave, rage”) + ‎-bundus → ‎furibundus (“raging, mad, furious”)

   ‎morior (“die”) + ‎-bundus → ‎moribundus (“dying; mortal”)

   ‎populor (“ravage, lay waste to”) + ‎-bundus → ‎populābundus (“laying waste, ravaging”)

First/second-declension adjective.