The name that is transliterated as “Thomas” in English is translated in Finnish Sign Language with the sign signifying “doubt” (referring to John 20:25). (Source: Tarja Sandholm)
“Thomas” in Finnish Sign Language (source )
In German Sign Language it is a sign that points fingers to the side of the body, referring to John 20:27.
“Thomas” in German Sign Language (source: Taub und katholisch )
See also The Confession of Thomas (icon) and Thomas with the risen Christ (image).