A small or minute insect of an order that includes the booklice. Many psocids are wingless and somewhat resemble lice or aphids, and most live on bark and among foliage.
- ‘Book lice is a species of insect called psocid which was given its common name as it used to live on the binding materials of old books.’
- ‘Most psocids live outdoors and have wings. They can be found on tree bark, tree and shrub foliage, or under stones. These psocids are known as 'barklice'.’
- ‘Psocids are common but harmless household pests, smaller than a pinhead, that can live in dry powdery type foods.’
Late 19th century: from modern Latin Psocidae (plural), from Psocus (genus name), from Greek psōkhein to grind.