■ noun
each of several projections on the rim of a wheel that engage with the links of a chain or with holes in film, tape, or paper.
(also sprocket wheel) a wheel with projections of this kind.

C16 (denoting a triangular piece of timber used in a roof): of unknown origin.
…
EngMac
sprocket
n. 1. (исто и sprocket-wheel) запченик.; 2. забец (на запченик)
…
Merriam-Webster Collegiate® Dictionary
sprock·et
Pronunciation: ‘sprä-kət
Function: noun
Etymology: origin unknown
Date: 1886

1 : a toothed wheel whose teeth engage the links of a chain
2 : a cylinder with teeth around the circumference at either end that project through perforations in something (as motion-picture film) to move it through a mechanism (as a projector)

…
Concise Oxford English Dictionary
rivet
‘rɪvɪt
■  noun a short metal pin or bolt for holding together two metal plates, its headless end being beaten out or pressed down when in place.
■  verb (rivets, riveting, riveted)
    join or fasten with a rivet or rivets.
    completely engross. ▶direct (one’s eyes or attention) intently.
 

riveter noun
riveting adjective
rivetingly adverb
 

ME: from OFr., from river ‘fix, clinch’.
…
EngMac
rivet
(fig)задржува поглед (на), заковува; (v)зацврстува, кове, приковува; навртка, железна чивија; навртка, железна чивија, заковка
…
English-Serbian dictionary
Rivet
Zakovica-Pricvrstiti-Prikovati-Zakivak
…
Merriam-Webster Collegiate® Dictionary
1riv·et
Pronunciation:     ‘ri-vət
Function:           noun
Etymology:          Middle English, clinch on a nail, rivet, from Old French, from river to attach, rivet, probably from rive border, edge, bank, from Latin ripa
Date:               15th century

: a headed pin or bolt of metal used for uniting two or more pieces by passing the shank through a hole in each piece and then beating or pressing down the plain end so as to make a second head
2rivet
Function:           transitive verb
Date:               15th century

1 : to fasten with or as if with rivets
2 : to upset the end or point of (as a metallic pin, rod, or bolt) by beating or pressing so as to form a head
3 : to fasten or fix firmly
4 : to attract and hold (as the attention) completely
 –riv·et·er noun