translation vs surtitle

translation and surtitle both are nouns.

Word	Noun	Adjective	Verb	Adverb
translation	Yes	No	No	No
surtitle	Yes	No	No	No

As nouns, surtitle is a hyponym of translation; that is, surtitle is a word with a more specific, narrower meaning than translation:

translation: a written communication in a second language having the same meaning as the written communication in a first language
surtitle: translation of the words of a foreign opera (or choral work) projected on a screen above the stage

Other hyponyms of translation include mistranslation, crib, pony, trot, retroversion, caption, subtitle, supertitle.

translation (noun)	surtitle (noun)
the act of uniform movement	translation of the words of a foreign opera (or choral work) projected on a screen above the stage
the act of changing in form or shape or appearance
a written communication in a second language having the same meaning as the written communication in a first language
rewording something in less technical terminology
a uniform movement without rotation
(genetics) the process whereby genetic information coded in messenger RNA directs the formation of a specific protein at a ribosome in the cytoplasm
(mathematics) a transformation in which the origin of the coordinate system is moved to another position but the direction of each axis remains the same