commensal adj.

word-forming element usually meaning "with, together," from Latin com, archaic form of classical Latin cum "together, together with, in combination," from PIE *kom- "beside, near, by, with" (compare Old English ge-, German ge-). The prefix in Latin sometimes was used as an intensive.

Before vowels and aspirates, it is reduced to co-; before -g-, it is assimilated to cog- or con-; before -l-, assimilated to col-; before -r-, assimilated to cor-; before -c-, -d-, -j-, -n-, -q-, -s-, -t-, and -v-, it is assimilated to con-, which was so frequent that it often was used as the normal form.

"high table land, in the U.S. Southwest, a broad and flat region between canyons or rivers," 1759, from Spanish mesa "plateau," literally "table," from Latin mensa "table" for sacred offerings or for meals (source of Romanian masa, Old French moise "table"), which de Vaan writes is probably the feminine of the past participle mensus ("measured") of metiri (from PIE root *me- (2) "to measure"),formed by analogy with pensus "weighed."  He compares Umbrian mefa, mefe, name of a certain sacrificial object, perhaps cake, and writes, "In Latin, the meaning then shifted from the offering itself to the object on which the offerings were placed."

"commensal existence or mode of living," 1870, from commensal + -ism.