Here are some ways to understand its meaning:
* Generous: A lavish gift is given with a lot of care and expense.
* Extravagant: A lavish party involves excessive spending on decorations, food, and entertainment.
* Luxurious: A lavish hotel suite is filled with high-quality amenities and comforts.
Example:
"They celebrated their anniversary with a lavish dinner at a five-star restaurant."
In this sentence, "lavishly" implies that the dinner was expensive, luxurious, and probably involved a lot of food and fancy decorations.