on-off
adjective uk/ˌɒnˈɒf/ us/ˌɑːnˈɑːf/
(SWITCH)
开关型的
that can be in two positions, either on or off
The basic model uses a simple on-off switch. 基础模型用一个简单的开关。
(RELATIONSHIP)
UK (US on-again, off-again)不连续的，断断续续的
that is not continuous; that stops and starts again
an on-off romance 断断续续的浪漫史
I need to add that this was not our first break-up; our relationship was on-off for about a year. 我需要加上一句，这不是我们第一次分手，我们这样断断续续有一年了。