altar cloth
/ˈɔːltə klɒθ/ /ˈɒltə klɒθ/noun
A cloth used to cover an altar; specifically (a) a cloth of white linen covering the top of the altar during the communion or Mass; (b) an ornamental altar frontal or superfrontal (now historical ).
Origin
Middle English; earliest use found in Trinity Cambridge Manuscript. From altar + cloth.