What does unlabelled mean?
Unlabelled means that something has no label, tag, or identifying mark attached to it. The word can describe physical objects, such as samples, packages, or containers, as well as information that has not yet been identified or classified. In scientific and data-related work, unlabelled specimens lack confirmed names or categories, while unlabelled data consists of examples without ground-truth annotations for training or evaluating a system. The term is neutral rather than negative: an unlabelled item may simply be awaiting identification. It is also useful when distinguishing a missing identifier from an intentionally generic or anonymous presentation. British English commonly spells the word with two l's, as in unlabelled, whereas US English generally uses one l, as in unlabeled. The prefix un- is especially productive here, expressing the absence of a label rather than the removal of one.
adjectiveNot marked with a label or identifying tag. In data science and related fields, it may also mean not identified or classified by a label.
- Not bearing a label, tag, or other identifying mark.
- Not identified or classified by a label, especially in data annotation and machine learning.
"The laboratory placed the unlabelled samples in separate containers for later identification."
"The box contained several unlabelled folders waiting to be sorted."
"The researchers used unlabelled images to test how accurately the model could classify them."
Unlabelled names the blank slate: an object, sample, or dataset whose identity has not yet been assigned.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Where does unlabelled come from?
Unlabelled was formed in English by combining the prefix un- with the word label. The English word label was borrowed from Old French label, through Medieval Latin labellum, ultimately reflecting a Latin diminutive associated with labellum. The same Latin family includes labellum, a related form meaning a small lip or lip-like structure, while the English base word developed its modern sense of an identifying mark or written description.
How unlabelled is actually used
Unlabelled is standard British spelling, while unlabeled is standard US spelling. The term is especially common in scientific, technical, and data-related contexts, where it describes specimens, records, or data without assigned identifiers or classifications.
Easily confused with unlabelled
Unlabelled is the usual British spelling, while unlabeled is the usual US spelling; they have the same meaning.
Unlabelled specifically lacks an identifying label or tag, whereas unmarked more broadly lacks any visible mark or indication.