I. wane 1 /weɪn/ BrE AmE verb [intransitive]
[ Language: Old English ; Origin: wanian ]
1 . if something such as power, influence, or a feeling wanes, it becomes gradually less strong or less important:
My enthusiasm for the project was waning.
The group’s influence had begun to wane by this time.
2 . when the moon wanes, you gradually see less of it OPP wax
⇨ wax and wane at ↑ wax 2 (4)
II. wane 2 BrE AmE noun
on the wane becoming smaller, weaker, or less important:
By the 5th century, the power of the Roman Empire was on the wane.