Týr 

Týr (/tɪər/; Old Norse: Týr, pronounced [tyːr]) is a god in Germanic mythology, a valorous and powerful member of the Æsir and patron of warriors and mythological heroes. In Norse mythology, which provides most of the surviving narratives about gods among the Germanic peoples, Týr sacrifices his hand to the monstrous wolf Fenrir, who bites it off when he realizes the gods have bound him. Týr is foretold of being consumed by the similarly monstrous dog Garmr during the events of Ragnarök.

The interpretatio romana[a] generally renders the god as Mars, the ancient Roman war god, and it is through that lens that most Latin references to the god occur. For example, the god may be referenced as Mars Thingsus (Latin 'Mars of the Assembly [Thing]') on 3rd century Latin inscription, reflecting a strong association with the Germanic thing, a legislative body among the ancient Germanic peoples. By way of the opposite process of interpretatio germanica, Tuesday is named after Týr ('Týr's day'), rather than Mars, in English and other Germanic languages.

In Old Norse sources, Týr is alternately described as the son of the jötunn Hymir (in Hymiskviða) or of the god Odin (in Skáldskaparmál). Lokasenna makes reference to an unnamed and otherwise unknown consort, perhaps also reflected in the continental Germanic record (see Zisa).

Due to the etymology of the god's name and the shadowy presence of the god in the extant Germanic corpus, some scholars propose that Týr may have once held a more central place among the deities of early Germanic mythology.

Origin of Tuesday

The modern English weekday name Tuesday comes from the Old English tīwesdæg, meaning 'day of Tīw'. It is cognate with Old Norse Týsdagr, Old Frisian Tīesdi, and Old High German Ziostag (Middle High German Zīstac). All of them stem from Late Proto-Germanic *Tiwasdag ('Day of *Tīwaz'), a calque of Latin Martis dies ('Day of Mars'; cf. modern Italian martedì, French mardi, Spanish martes). This attests to an early Germanic identification of *Tīwaz with Mars.
Germanic weekday names for Tuesday that do not transparently extend from the above lineage may also ultimately refer to the deity, including Middle Dutch Dinxendach and Dingsdag, Middle Low German Dingesdach, and Old High German Dingesdag (modern Dienstag). These forms may refer to the god's association with the thing (*þingsaz), a traditional legal assembly common among the ancient Germanic peoples with which the god is associated. This may be either explained by the existence of an epithet, Thingsus (*Þingsaz 'thing-god'), frequently attached to Mars (*Tīwaz), or simply by the god's strong association with the assembly.[