A noun translated “crow” (SD/426). Tolkien listed this noun in two forms, khâu and khô, both as examples of seemingly uniconsonantal nouns that prehistorically were biconsonantal (from prehistoric ✶khaw). Most authors have suggested these are simply variations on the same noun illustrating different paths of phonetic development (AAD/18, AL/Adûnaic). Another interesting possibility is that khâu is an (archaic?) subjective form of khô, produced from the usual a-fortification of primitive ✶khaw → ✶khāw, which would develop phonetically in Classical Adûnaic to khâu and khô. As support for this idea, the plural form of khâu is given as khāwī(m), which appears to include the subjective plural suffix -im.

This line of reasoning is quite speculative. Nevertheless, it is probably easier to use the form khô over khâu, since the inflections of khô would be more regular: plural khôi, dual *khôwat, objective *khôwu, etc.