- kaleidoscopeAn instrument consisting of a tube containing mirrors and loose, colourful beads or other objects; when the tube is looked into and rotated, a succession of symmetrical designs can be seen.
- CaloA surname.
- calotypeA talbotype.
- kaleidographA late 19th or early 20th century device for duplicating documents that use colored ink, consisting of a tray with a rubbery substance that takes an impression of the document and then transfers it onto blank sheets of paper.
- kalologyThe study of beauty; aesthetics