This word usually means breadfruit (= 'skull'). Its fruit resembles a human skull, and it is a most important fruit because of this and because of its nutricious value. However, on Easter Island breadfruit couldn't grow and another plant seems to have served as a substitute, Solanum nigrum, called poporo:

This plant is - according to bishop Jaussen's documentations of what Metoro Tau'a Ure told him - one species of the interesting family of plants named Solanum. It was used for obtaining colour for tattooing. There are though several different types of glyphs showing this plant, and possibly not all of these types imply colour for tattooing. Every gift from nature was taken care of to the utmost.

Barthel suggests the plant to be Solanum nigrum. As nigrum means black, the glyph perhaps was used for 'black'. Barthel points out that on the Marquesas they counted the fruits from the breadfruit trees in fours, perhaps thereby explaining the four 'berries' in this type of glyph.

The breadfruit did not grow on Easter Island and the berries of Solanum nigrum were eaten in times of famine.

Barthel also informs us that the Maori singers in New Zealand, where the breadfruit did not grow, 'translated' kuru (= breadfruit) in the old songs, from the times when their forefathers lived in a warmer climate, into poporo (= Solanum nigrum). And according to Metoro the type of glyph above stood for poporo.

Barthel further compares with the word koporo on Mangareva. The poor crop of breadfruits at the end of the harvest season was called mei-koporo, where mei stood for breadfruit. On other islands breadfruit was called kuru, except on the Marquesas which also used the word mei. Koporo was a species of nightshade.

Métraux:

"The low entrances of houses were guarded by images of wood or of bark cloth, representing lizards or rarely crayfish. The bark cloth images were made over frames of reed, and were called manu-uru, a name given also to kites, masks, and masked people ..."