Noun: aculeus (aculei) u'kyoo-lee-us
- A stiff sharp-pointed plant process
"The rose stem was covered in sharp aculei"
- A sharp-pointed process especially a sting of a hymenopterous insect
"The bee's aculeus delivers venom when it stings"
Derived forms: aculei
Type of: enation, plant process, stinger
Encyclopedia: Aculeus