in-and-out
/ˈɪnəndˈaʊt/adjective
informal <非正式>
1
- involving inward and outward movement, especially rapid entrance and exit（尤指快速）进出的：
smuggling drugs was a quick in-and-out operation.
走私毒品是快速进出的活动。
2
- inconsistent and unreliable前后不一的, 时好时坏的：
this horse is a notoriously in-and-out performer.
这匹马是臭名昭著时好时坏的表演者。