capillary column

in chromatography
https://doi.org/10.1351/goldbook.C00793
A general term for columns having a small diameter. A capillary column may contain a packing or have the stationary phase supported on its inside wall. The former case corresponds to packed capillary column while the latter case corresponds to an open-tabular column. Due to the ambiguity of this term its use without an adjective is discouraged.
Source:
PAC, 1993, 65, 819. (Nomenclature for chromatography (IUPAC Recommendations 1993)) on page 831 [Terms] [Paper]