NEST

noun

1. A structure built by a bird as a place to incubate eggs and rear young.
2. A place used by another mammal, fish, amphibian or insect, for depositing eggs and hatching young.
3. A snug, comfortable, or cosy residence or job situation.

verb

1. (of animals) To build or settle into a nest.
2. To settle into a home.
3. To successively neatly fit inside another.