groove
n. countablen. a long, narrow cut or line in a hard surface. It can also mean a steady, enjoyable rhythm in music that makes you want to dance.
n. a long, narrow channel or furrow cut into a hard material; also refers to a rhythmic pattern in music that establishes a consistent, infectious feel.
The sliding door fits into a narrow groove in the floor.
The needle follows the groove on the record to play the music clearly.
Once the drummer established a steady groove, the rest of the band relaxed into the performance, allowing for more experimental solos during the bridge.
From Middle English grov, grove, groof, grofe (“cave; pit; mining shaft”), probably from Old Norse gróf (“pit”) or from Middle Dutch groeve (“furrow, ditch”), both from Proto-West Germanic grōbu, from Proto-Germanic grōbō (“groove, furrow”), from Proto-Indo-European *gʰrebʰ- (“to dig, scrape, bury”). Cognate with Cimbrian gruuba (“gorge, ravine”), Dutch groef, groeve (“groove; pit, grave”), German Grube (“ditch, pit”), Luxembourgish Grouf (“pit, mine”), Mòcheno gruab (“mine”), Icelandic gróf (“pit, hollow”), Gothic 𐌲𐍂𐍉𐌱𐌰 (grōba, “foxhole”), Serbo-Croatian grèbati (“scratch, dig”). Related to Old English grafan (“to dig”). More at grave.
Often used metaphorically in the phrase 'in the groove' to describe performing well or being in a state of flow.