Black = free: a nice case of polysemy in Songhay, and its converse

Looking through Jeffrey Heath's 1998 dictionary of Koyra Chiini, the Songhay language spoken in and around Timbuktu, I was struck by the following entry:

bibi * a) [intr] be black, dark [cf bii 2] [INTENS: tirik! T, fi! N] * be freeborn, noble (not a slave) * LOCUT: bañña nda bibi slave and freeman alike * [final in compounds involving sorcery, => čiini-bibi * b) [adj] black, dark * c. [n] soot, burnt residue.

It contrasts satisfyingly with the sort of polysemy you tend to get for "black" on the other shore of the Sahara, as in this Kabyle entry from Dallet 1982:

akli (wa), aklan (wa) || Negro. || Slave, servant. || Butcher; profession reserved for the inferior class of aklan (slaughterer and wholesale and retail vendor in the market.) || Male first name often given to a Kabyle child as a prophylactic measure (against envious gazes and the evil eye.) Antonym: aḥerri [free].

It would be interesting to examine the connotations of "black" in more languages...