der Stachel
stinger
A pointed organ, often associated with venom, in certain insects or animals, used for stinging.
Die Wespe hat ihren Stachel in seiner Haut hinterlassen.
The wasp left its stinger in his skin.

stinger / thorn
Loading your saved state.
stinger
A pointed organ, often associated with venom, in certain insects or animals, used for stinging.
Die Wespe hat ihren Stachel in seiner Haut hinterlassen.
The wasp left its stinger in his skin.

'Der Stachel' (stinger/thorn) is the tool with which something stings. The word is closely related to the verb 'stechen' (to sting/prick), which describes the action of stinging or pricking.
Vorsicht, diese Wespen stechen, wenn sie sich bedroht fühlen.
Careful, these wasps sting when they feel threatened.
The context reveals the meaning. With animals like bees, it is the stinging organ; with plants like roses, it is the pointed growth; and with feelings like envy, it is emotional pain.
Die Biene verlor beim Stechen ihren Stachel.
The bee lost its stinger when it stung.
When talking about insect stings, people often say that you have to 'den Stachel entfernen' (remove the stinger) or 'herausziehen' (pull it out). The insect itself can 'einen Stachel hinterlassen' (leave a stinger behind).
Nach dem Bienenstich musste ich schnell den Stachel entfernen.
After the bee sting, I had to remove the stinger quickly.
In the figurative meaning, 'Stachel' (sting) describes emotional pain. Typical phrases are 'der Stachel der Eifersucht' (the sting of jealousy), 'der Stachel des Neides' (the sting of envy), or that a remark 'einen Stachel hinterlässt' (leaves a sting).
Der Stachel des Zweifels blieb auch nach seiner Erklärung.
The sting of doubt remained even after his explanation.
tip / top / lace
'die Spitze' and 'der Stachel' can both refer to something pointed. 'die Spitze' is generally the narrow, pointed end of an object, for example on a pencil or knife. 'der Stachel' is a pointed part on an animal or plant and often serves for stinging or protection. The words can be confused because a stinger or thorn also has a tip. But not every tip is a 'Stachel'. For tools or objects, you usually say 'Spitze'; for bees, roses, or cacti, 'Stachel' fits.

Beim Pflücken blieb ein Stachel der Rose in Lenas Finger stecken.
While picking the rose, a thorn got stuck in Lena's finger.
Die Spitze des Bleistifts ist abgebrochen, deshalb kann ich nicht schreiben.
The tip of the pencil has broken off, so I can't write.