Syriac

rāˀtā, raˀtā, rātā - lung (LSyr. 705, SL 1425)

PWS
*riˀ-at- - lung (SED I No. 224)
Usually compared to Akk. irtu, Ugr. ˀirt. ‘breast’; reconstruction of two different roots probably related by metathesis (cf. *ˀir(r)-at- ‘chest, breast’) is preferable.