serrated (adj.)

"notched on the edge like a saw," 1660s, from Latin serratus "sawlike, notched like a saw," from serra "a saw" (also a name of a type of serrated battle formation), a word of unknown origin. De Vaan suggests a connection to Latin sario 'to hoe, weed," and a PIE source in *sers- "cutting off." Related: Serrated; serrating.

"range of hills or mountains," 1610s, from Spanish sierra "jagged mountain range," literally "saw," from Latin serra "a saw" (compare serrated), which is of unknown origin. De Vaan suggests a PIE *sers-h- "cutting off," and within Latin a possible connection with sarire "to hoe, weed." The word figures in many mountain-chain names in Spain and regions it explored and colonized.