Undulating means rising and falling in gentle waves. Undulating hills, an undulating road, undulating country.
It is a favourite of estate agents and race organisers, and in the second case it is a warning — an undulating course means hills nobody wants to call hills. The word describes a shape and a motion at once, from the Latin for a wave.
1adjectiveundulatingRising and falling in gentle waves.
“The road wound through undulating farmland dotted with sheep.”
undulating is a quality of shape.
Proto-Indo-European
*wed-
Latin
unda — wave
New Latin
undulātus
English
undulate
English, today
undulating
undulate 1664; New Latin undulātus, the perfect passive participle of undulō (see -ate), from an unattested *undula (“small wave”), diminutive of Latin unda (“wave”).
Etymology from Wiktionary, CC BY-SA