a combining form with the meanings âheight,â âtip end,â âextremities of the body,â used in the formation of compound words: acrophobia. Also, especially before a vowel, acr-. Origin of acro-. < Greek, combining form of Ã¡kros topmost, highest; akin to Latin Äcer sharp.
â¢ CANTUS FIRMUS (noun) The noun CANTUS FIRMUS has 1 sense: 1. a melody used as the basis for a polyphonic composition. Familiarity information: CANTUS FIRMUS used as a noun is very rare. Dictionary entry details.
The Firmicutes (Latin: firmus, strong, and cutis, skin, referring to the cell wall) are a phylum of bacteria, most of which have Gram-positive cell wall structure. A few, however, such as Megasphaera, Pectinatus, Selenomonas and Zymophilus, have a porous pseudo-outer membrane that causes them to stain Gram-negative.