I learned a new loanword today, from the French- piton. To quote the source for this useful phrase, 2metaldog
The best translation I have for it is: the little thing that doesn't have a name on the end of the bigger thing that does have a name. An example of this would be that little plastic thing on the end of shoelaces. That's a piton. Or the little bit of rubber that sticks out after you tie a knot in a ballon that you've just blown up. That's a piton, too.
Someone in the comments mentions that the plastic thingy at the end of the shoelace is actually an aglet, which is fine, but piton will do as well. Especially in these latter velcro days. (BTW-- do not put your toddlers into lace-ups, ye who have or will have toddlers. No eighteen month old can resist the urge to pull on the laces, run away, trip on the things and wail mightily. To be consoled by their caregiver- 'Aaron Elliot, tell your Mummy- velcro.')