pinnacle (n.) Look up pinnacle at Dictionary.com
c.1300, "mountain, peak, promontory," from Old French pinacle "top, gable" (13c.) and directly from Late Latin pinnaculum "peak, pinnacle, gable," extended form (via diminutive suffix, but not necessarily implying smallness) of Latin pinna "peak, point," (see pin (n.1)). Figurative use is attested from c.1400.