nose-picking1
/ˈnəʊzˌpɪkɪŋ/noun
The action of picking the nose, especially habitually.
Origin
Early 20th century; earliest use found in The Kansas City Star. From nose + picking.
nose-picking2
/ˈnəʊzˌpɪkɪŋ/adjective
Of a person: that picks the nose, especially habitually.
Origin
1960s; earliest use found in Arthur Koestler (1905–1983), novelist and journalist. From nose + picking.