nesting

Concise Oxford English Dictionary © 2008 Oxford University Press:
nest/nest/

▶noun

• 1 a structure or place made or chosen by a bird for laying eggs and sheltering its young.

  ■ a place where an animal or insect breeds or shelters.

  ■ a snug or secluded retreat.

  ■ a bowl-shaped object.

• 2 a place filled with undesirable people or things: a nest of spies.

• 3 a set of similar objects of graduated sizes, fitting together for storage.

▶verb

• 1 use or build a nest.

• 2 fit (an object or objects) inside a larger one.

• 3 (especially in computing and linguistics) place in a lower position in a hierarchy.

– derivatives
nester noun,
nestful noun (pl. nestfuls).

– origin OE nest, of Gmc origin.