1829, American English slang, of unknown origin, perhaps related to British dialectal mose about "go around in a dull, stupid way." Or perhaps from Spanish vamos (see vamoose). Related: Moseyed; moseying.
To move along, esp to walk slowly; saunter; ease on: A mild river that moseyed at will/ The Wheaton cruiser moseyed on by me and turned back toward town
[1829+; perhaps fr Spanish vamos; perhaps fr British dialect mose about, ''walk in a stupid manner'']