The Kēleni see one’s kin as threads in a woven cloth. One’s makīri are the up and down threads (warp) and one’s maþūskīri are the side to side threads (weft). [See Wikipedia article on Weaving for more information on weaving.]
At it’s narrowest, maþūskīri means one’s father’s matrilineal kin. The meaning has expanded to include close friends, colleagues one interacts with every day, and other people one can reliably ask a favor of.