latus.

Earlier *tlātus, from Proto-Italic *tlātos, from Proto-Indo-European *tl̥h₂tós, from the root *telh₂-. Compare Ancient Greek τλάντος (tlántos, “bearing, suffering”), τολμέω (tolméō, “to carry, bear”), τελαμών (telamṓn, “broad strap for bearing something”), Ἄτλας (Átlas, “the 'Bearer' of Heaven”), Lithuanian tiltas (“bridge”), Sanskrit तुला (tulā, “balance”), तुलयति (tulayati, “lifts up, weighs”), Latin tollō (“to bear, support”), tulī (“bore”), tolerō (“bear, endure”), tellūs (“bearing earth”), Old English þolian (“to endure”) (English thole), Old Armenian թողում (tʻołum, “to allow”), Persian ترازو (tarâzu, “balance, scales”).

Uncertain. Historically, the term has been compared to Ancient Greek στέλλω (stéllō, “to make ready”) and Old Church Slavonic стьлати (stĭlati, “to spread, stretch”), on which basis a root *stelH- had been reconstructed. According to this theory, the Latin term could be derived from *stl̥Htós. However, the root of the aforementioned cognate is now largely reconstructed as *stel-, which could not produce the Latin term. De Vaan suggests a possible comparison to Old Irish con·slá (“to depart”), in which case the Latin word would have developed semantically from "going apart, spreading" to "wide." This theory does require a slightly irregularly development of the initial *slā- to Latin *stlā-, whence finally lā-. However, a similar sound change may be attested in līs.

Uncertain. Some indicate Proto-Indo-European *pleth₂- (“flat”) or *stelh₃- (“broad”), in which latter case it would be related with etymology 2 above; cf. also later m.