small, strong European species of falcon, late 14c., merlioun (perhaps early 14c.), from Anglo-French merilun, a shortened form of Old French esmerillon "merlin, small hawk" (12c., Modern French émerillon), from Frankish *smiril or some other Germanic source (compare Old High German smerlo, German Schmerl "merlin"). Spanish esmerejon, Italian smeriglio also are Germanic loan-words. OED rejects connection with Latin merula "blackbird."
updated on December 29, 2018