hilo

thread, yarn, string; linen; edge of something sharp; crosshair, reticule; ellipsis of hilo de oro, type of stinging jellyfish in Guanacaste, Costa Rica

“Los magos, los acróbatas, los clowns / Mueven los hilos con habilidad”

From Old Spanish filo, from Latin fīlum. Doublet of filo. Although both were inherited, it is not fully certain why the two diverged and why filo, preserving the initial -f- from Old Spanish, took on the sense of “edge”, while hilo maintained that of “string, thread” (in line with the original Latin meaning). Cognate with English file.