Like a small ring.
The plural form is anellini.
This is an Italian word, but you'll see it in reference to anellini pasta (think SpaghettiOs)
or (where I saw it) anellino beans.
Etymology: Italian. 'Anello' means 'ring'.
Many English words come directly from the Latin word for 'little ring' (annulus), such as annular eclipse (an eclipse where the sun appears as an annulus around the moon) and annelids (ringed or segmented worms such as earthworms).