Cloth (uncountable) usually refers to material made of cotton, wool etc. that is used for making clothes: ‘The tailor took my measurements and then showed me several rolls of cloth.’
Costume = (1) (countable) a set of clothes worn during a performance by an actor, clown, etc.: ‘She used to work for a theatre company, designing and making costumes.’ (2) (Countable) a set of clothes that are typical of a particular country or historical period: ‘The castle guides were dressed up in Elizabethan costume.’
