from the GNU version of the Collaborative International Dictionary of English
- adj. Consisting of two iambic dimeters catalectic, the last of which lacks the final syllable; -- said of a kind of verse.
from The Century Dictionary and Cyclopedia
- Constituting a galliambus; consisting of galliambi: an epithet of a variety of Ionic verse said to have first come into use among the Galli or priests of the Phrygian Cybele. See galliambus.
- n. A galliambus; a verse consisting of four Ionics a minore with variations and substitutions.
Sorry, no etymologies found.
He has harmony without melody; he invents and executes marvellous variations upon verse; he has footed the tight-rope of the galliambic measure and the swaying planks of various trochaic experiments; but his resolve to astonish is stronger than his desire to charm, and he lets technical skill carry him into such excesses of ugliness in verse as technical skill carried Liszt, and sometimes Berlioz, in music.
The accident of its being the only Latin poem extant in the peculiar galliambic metre has combined with the nature of the subject  to induce a tradition about it as though it were the most daring and extraordinary of Catullus 'poems.
The metre is galliambic, a rhythm proper to the hymns of Cybele, but of which no primitive Greek example remains.