slow (adj.) Look up slow at Dictionary.com
Old English slaw "inactive, sluggish," also "not clever," from Proto-Germanic *slæwaz (cf. Old Saxon sleu "blunt, dull," Middle Dutch slee, Dutch sleeuw "sour, tart, blunt," Old High German sleo "blunt, dull," Old Norse sljor, Danish sløv, Swedish slö "blunt, dull"). Meaning "taking a long time" is attested from early 13c. Meaning "dull, tedious" is from 1841. Slowpoke is first recorded 1848.
slow (v.) Look up slow at Dictionary.com
Old English slawian, from the source of slow (adj.); modern use may be a 16c. re-formation. Related: Slowed; slowing.