• 巣す — nest / den / home
• 巣立すだつ — to leave the nest / become independent
• 巣箱すばこ — birdhouse / nesting box
• 病巣びょうそう — lesion / source of disease
• 営巣えいそう — nesting / building a nest
• 卵巣らんそう — ovary

The character 巣 is symbolic: a bird under a roof structure, suggesting a protected home. The kanji reflects both literal and metaphorical ideas of shelter and origin.

この鳥とりは 巣すを作つくっています。
This bird is building a nest.

子こどもたちが 巣立すだちました。
The children have flown the nest (become independent).

森もりには 多おおくの巣すがあります。
There are many nests in the forest.

🎧 The kunyomi す is used when referring directly to a bird's or animal's nest, while ソウ is more common in compounds like 巣箱 or 病巣.