diff --git a/spacy_llm/pipeline/llm.py b/spacy_llm/pipeline/llm.py
index 1c3365d4..70003a8b 100644
--- a/spacy_llm/pipeline/llm.py
+++ b/spacy_llm/pipeline/llm.py
@@ -138,10 +138,15 @@ def labels(self) -> Tuple[str, ...]:
             labels = self._task.labels
         return labels
 
-    def add_label(self, label: str) -> int:
+    def add_label(self, label: str, label_definition: Optional[str] = None) -> int:
         if not isinstance(self._task, LabeledTask):
             raise ValueError("The task of this LLM component does not have labels.")
-        return self._task.add_label(label)
+        return self._task.add_label(label, label_definition)
+
+    def clear(self) -> None:
+        if not isinstance(self._task, LabeledTask):
+            raise ValueError("The task of this LLM component does not have labels.")
+        return self._task.clear()
 
     @property
     def task(self) -> LLMTask:
diff --git a/spacy_llm/tasks/builtin_task.py b/spacy_llm/tasks/builtin_task.py
index fa565a97..3c4ef027 100644
--- a/spacy_llm/tasks/builtin_task.py
+++ b/spacy_llm/tasks/builtin_task.py
@@ -312,14 +312,25 @@ def _extract_labels_from_example(self, example: Example) -> List[str]:
     def labels(self) -> Tuple[str, ...]:
         return tuple(self._label_dict.values())
 
-    def add_label(self, label: str) -> int:
+    def add_label(self, label: str, label_definition: Optional[str] = None) -> int:
+        """Add a label to the task"""
         if not isinstance(label, str):
             raise ValueError(Errors.E187)
         if label in self.labels:
             return 0
         self._label_dict[self._normalizer(label)] = label
+        if label_definition is None:
+            return 1
+        if self._label_definitions is None:
+            self._label_definitions = {}
+        self._label_definitions[label] = label_definition
         return 1
 
+    def clear(self) -> None:
+        """Reset all labels."""
+        self._label_dict = {}
+        self._label_definitions = None
+
     @property
     def normalizer(self) -> Callable[[str], str]:
         return self._normalizer
diff --git a/spacy_llm/tests/tasks/test_ner.py b/spacy_llm/tests/tasks/test_ner.py
index 7d7c8c82..97512ca6 100644
--- a/spacy_llm/tests/tasks/test_ner.py
+++ b/spacy_llm/tests/tasks/test_ner.py
@@ -992,7 +992,41 @@ def test_add_label():
     doc = nlp(text)
     assert len(doc.ents) == 0
 
+    for label, definition in [
+        ("PERSON", "Every person with the name Jack"),
+        ("LOCATION", None),
+    ]:
+        llm.add_label(label, definition)
+    doc = nlp(text)
+    assert len(doc.ents) == 2
+
+
+@pytest.mark.external
+@pytest.mark.skipif(has_openai_key is False, reason="OpenAI API key not available")
+def test_clear_label():
+    nlp = spacy.blank("en")
+    llm = nlp.add_pipe(
+        "llm",
+        config={
+            "task": {
+                "@llm_tasks": "spacy.NER.v3",
+            },
+            "model": {
+                "@llm_models": "spacy.GPT-3-5.v1",
+            },
+        },
+    )
+
+    nlp.initialize()
+    text = "Jack and Jill visited France."
+    doc = nlp(text)
+
     for label in ["PERSON", "LOCATION"]:
         llm.add_label(label)
     doc = nlp(text)
     assert len(doc.ents) == 3
+
+    llm.clear()
+
+    doc = nlp(text)
+    assert len(doc.ents) == 0
diff --git a/spacy_llm/ty.py b/spacy_llm/ty.py
index 0673b1d0..c07c0acb 100644
--- a/spacy_llm/ty.py
+++ b/spacy_llm/ty.py
@@ -136,7 +136,10 @@ class LabeledTask(Protocol):
     def labels(self) -> Tuple[str, ...]:
         ...
 
-    def add_label(self, label: str) -> int:
+    def add_label(self, label: str, label_definition: Optional[str] = None) -> int:
+        ...
+
+    def clear(self) -> None:
         ...