1. 小结节;小瘤
A nodule is a small round lump that can appear on your body and is a sign of an illness.

2. (植物的)根瘤，根结
A nodule is a small round lump which is found on the roots of certain plants.

1. a small node

2. (mineralogy) a small rounded lump of mineral substance (usually harder than the surrounding rock or sediment)

3. small rounded wartlike protuberance on a plant

Synonym: tubercle