nesting
nounUK /ˈnestɪŋ/
US /ˈnestɪŋ/
The act of building or using a nest.
The birds are nesting in the tall tree.
OTHER MEANINGS
2. Arranging things so that smaller ones fit inside bigger ones.
She stacked the bowls by nesting them one inside another.
3. Preparing a home for a baby, especially during pregnancy.
They spent the weekend nesting before the baby arrived.
4. Placing code structures inside one another in computing.
The program uses nesting to put loops inside loops.