un·du·la·tion
noun/ˌʌndʒəˈleɪʃn/
/ˌʌndʒəˈleɪʃn/
[countable, uncountable]- a smooth, curving shape or movement like a series of waves
波浪形；起伏；波动；荡漾 - The road followed the undulations of the landscape.
道路顺着地形的起伏而行。
- The road followed the undulations of the landscape.